Respiratory syncytial virus (RSV) vaccine

ABSTRACT

The present invention relates to an mRNA sequence, comprising a coding region, encoding at least one antigenic peptide or protein of RSV infections Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof. Additionally the present invention relates to a composition comprising a plurality of mRNA sequences comprising a coding region, encoding at least one antigenic peptide or protein of RSV infections Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof. Furthermore it also discloses the use of the mRNA sequence or the composition comprising a plurality of mRNA sequences for the preparation of a pharmaceutical composition, especially a vaccine, e.g. for use in the prophylaxis or treatment of RSV infections Respiratory syncytial virus (RSV) infections. The present invention further describes a method of treatment or prophylaxis of RSV infections using the mRNA sequence.

The present application is a continuation of International Application No. PCT/EP2014/002301, filed Aug. 21, 2014, which claims priority benefit of European Application No. PCT/EP2013/002518, filed Aug. 21, 2013, the entire text of each of the above referenced disclosures being specifically incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an mRNA sequence, comprising a coding region, encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof. Additionally the present invention relates to a composition comprising a plurality of mRNA sequences comprising a coding region, encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof.

Furthermore it also discloses the use of the mRNA sequence or the composition comprising a plurality of mRNA sequences for the preparation of a pharmaceutical composition, especially a vaccine, e.g. for use in the prophylaxis or treatment of RSV infections. The present invention further describes a method of treatment or prophylaxis of RSV infections using the mRNA sequence.

The global medical need and economic impact of RSV is very high. It is the most important cause of acute lower respiratory tract infections (ALRIs) that result in hospital visits during infancy and early childhood. For example, in the United States, more than 60% of infants are infected by RSV during their first RSV season, and nearly all have been infected by 2-3 years of age. Approximately 2.1 million US children less than 5 years of age are treated for RSV disease each year: 3% as inpatients, 25% in emergency departments, and 73% in pediatric practices. Globally, among children less than five years of age, RSV causes an estimated 33.8 million ALRIs each year (more than 22% of all ALRIs), resulting in 66 000-199 000 deaths, 99% of which occur in developing countries. RSV is also a common cause of respiratory disease among the elderly, resulting in as many hospitalizations as influenza in a heavily influenza-immunized population. RSV spreads by respiratory droplets and close contact with infected persons or contaminated objects. In temperate climates, there is an annual winter epidemic. Infants are at highest risk for severe RSV disease in their first 6 months, and hospitalization peaks at 2-3 months of age. Preterm birth and cardiopulmonary disease are risk factors for severe RSV disease. RSV infection of infants elicits partially protective immunity, which appears to wane more rapidly than immunity against most other respiratory viruses. Most children infected with RSV during their first year are re-infected the next year, generally with less severe disease. Re-infections continue throughout life, often with upper respiratory tract symptoms, and sometimes with lower respiratory tract or sinus involvement. Recommended treatment of RSV bronchiolitis consists primarily of respiratory support and hydration. No specific anti-viral therapy is recommended. The neutralizing monoclonal antibody Palivizumab is used for prophylaxis of infants at highest risk for severe infection but is too expensive and impractical for universal use. Currently, there is no licensed RSV vaccine, and developing a safe and effective RSV vaccine is a global public health priority.

In a vaccine trial in the 1960s, infants and young children were immunized with a formalin-inactivated whole virion RSV preparation (FIRSV) or an equivalent paramyxovirus preparation (FIPIV). Five percent of the subjects who were immunized with FI-PIV and then naturally infected by RSV during the next RSV season were hospitalized; 80% of those who were immunized with FI-RSV and then infected by RSV were hospitalized, and two children died. This enhancement of an RSV infection due to vaccination is a specific problem for the development of vaccines against RSV infections (reviewed in Shaw et al. Curr Opin Virol. 2013 June; 3(3):332-42. doi: 10.1016/j.coviro.2013.05.003. Epub 2013 May 30.).

Therefore, Respiratory syncytial virus (RSV) infections are the greatest remaining unmet infant vaccine need in developed countries and an important unmet infant vaccine need worldwide. More than 40 years of effort have not yet resulted in a licensed RSV vaccine for humans.

In summary, RSV which belongs to the virus family of Paramyxoviridae, is one of the most contagious pathogens and makes a substantial contribution to severe respiratory tract infections in infants, the elderly and immunocompromised patients.

As mentioned above, currently a humanised monoclonal antibody against the viral surface F protein is the only prophylactic product on the market which is recommended for infants considered at high risk including pre-term infants and infants with chronic lung disease (The IMpact-RSV Study Group. 1998. Palivizumab, a Humanized Respiratory Syncytial Virus Monoclonal Antibody, Reduces Hospitalization From Respiratory Syncytial Virus Infection in High-risk Infants. Pediatrics, 102(3), S. 531-537, Tablan et al. 2003. Guidelines for preventing health-care—associated pneumonia, 2003: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee. MMWR. Recommendations and Reports: Morbidity and Mortality Weekly Report. Recommendations and Reports/Centers for Disease Control, 53(RR-3), S. 1-36.).

Recent studies with animal models demonstrated that sufficient amounts of neutralising antibodies targeting RSV F protein limit viral replication leading to a less severe course of disease (Singh, S. R. et al., 2007. Immunogenicity and efficacy of recombinant RSV-F vaccine in a mouse model. Vaccine, 25(33), S. 6211-6223, Zhan, X. et al., 2007. Respiratory syncytial virus (RSV) F protein expressed by recombinant Sendai virus elicits B-cell and T-cell responses in cotton rats and confers protection against RSV subtypes A and B. Vaccine, 25(52), 5.8782-8793, Vaughan, K., et al., 2005. DNA immunization against respiratory syncytial virus (RSV) in infant rhesus monkeys. Vaccine, 23(22), S. 2928-2942).

Moreover, it could be shown that a balanced regulatory and effector T cell function is required for viral clearance and reduction of severity of illness (Liu, J. et al., 2010. Epitope-specific regulatory CD4 T cells reduce virus-induced illness while preserving CD8 T-cell effector function at the site of infection. Journal of Virology, 84(20), S. 10501-10509).

Despite the above mentioned humanised monoclonal antibody, live-attenuated vaccine viruses were developed which elicit a strong immune response, but which are not recommended for use in the specific target groups (infants, children, the elderly and immunocompromised patients). Also, DNA vectors expressing RSV F protein which bears B-cell epitopes were used to induce the production of neutralizing antibodies. In this context, WO 2008/077527 and WO 96/040945 disclose vectors comprising DNA sequences encoding RSV F protein for the use as vaccines. However, the use of DNA as a vaccine may be dangerous due to unwanted insertion into the genome, possibly leading to interruption of functional genes and cancer or the formation of anti-DNA antibodies.

Therefore it is the object of the underlying invention to provide an mRNA sequence coding for antigenic peptides or proteins of Respiratory syncytial virus (RSV) for the use as vaccine for prophylaxis or treatment of RSV infections, particularly in infants, the elderly and immunocompromised patients.

These objects are solved by the subject matter of the attached claims. Particularly, the objects underlying the present invention are solved according to a first aspect by an inventive mRNA sequence comprising a coding region, encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof.

For the sake of clarity and readability the following scientific background information and definitions are provided. Any technical features disclosed thereby can be part of each and every embodiment of the invention. Additional definitions and explanations can be provided in the context of this disclosure.

Immune System:

The immune system may protect organisms from infection. If a pathogen breaks through a physical barrier of an organism and enters this organism, the innate immune system provides an immediate, but non-specific response. If pathogens evade this innate response, vertebrates possess a second layer of protection, the adaptive immune system. Here, the immune system adapts its response during an infection to improve its recognition of the pathogen. This improved response is then retained after the pathogen has been eliminated, in the form of an immunological memory, and allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered. According to this, the immune system comprises the innate and the adaptive immune system. Each of these two parts contains so called humoral and cellular components.

Immune Response:

An immune response may typically either be a specific reaction of the adaptive immune system to a particular antigen (so called specific or adaptive immune response) or an unspecific reaction of the innate immune system (so called unspecific or innate immune response). The invention relates to the core to specific reactions (adaptive immune responses) of the adaptive immune system. Particularly, it relates to adaptive immune responses to infections by viruses like e.g. RSV infections. However, this specific response can be supported by an additional unspecific reaction (innate immune response). Therefore, the invention also relates to a compound for simultaneous stimulation of the innate and the adaptive immune system to evoke an efficient adaptive immune response.

Adaptive Immune System:

The adaptive immune system is composed of highly specialized, systemic cells and processes that eliminate or prevent pathogenic growth. The adaptive immune response provides the vertebrate immune system with the ability to recognize and remember specific pathogens (to generate immunity), and to mount stronger attacks each time the pathogen is encountered. The system is highly adaptable because of somatic hypermutation (a process of increased frequency of somatic mutations), and V(D)J recombination (an irreversible genetic recombination of antigen receptor gene segments). This mechanism allows a small number of genes to generate a vast number of different antigen receptors, which are then uniquely expressed on each individual lymphocyte. Because the gene rearrangement leads to an irreversible change in the DNA of each cell, all of the progeny (offspring) of that cell will then inherit genes encoding the same receptor specificity, including the Memory B cells and Memory T cells that are the keys to long-lived specific immunity. Immune network theory is a theory of how the adaptive immune system works, that is based on interactions between the variable regions of the receptors of T cells, B cells and of molecules made by T cells and B cells that have variable regions.

Adaptive Immune Response:

The adaptive immune response is typically understood to be antigen-specific. Antigen specificity allows for the generation of responses that are tailored to specific antigens, pathogens or pathogen-infected cells. The ability to mount these tailored responses is maintained in the body by “memory cells”. Should a pathogen infect the body more than once, these specific memory cells are used to quickly eliminate it. In this context, the first step of an adaptive immune response is the activation of naïve antigen-specific T cells or different immune cells able to induce an antigen-specific immune response by antigen-presenting cells. This occurs in the lymphoid tissues and organs through which naïve T cells are constantly passing. Cell types that can serve as antigen-presenting cells are inter alia dendritic cells, macrophages, and B cells. Each of these cells has a distinct function in eliciting immune responses. Dendritic cells take up antigens by phagocytosis and macropinocytosis and are stimulated by contact with e.g. a foreign antigen to migrate to the local lymphoid tissue, where they differentiate into mature dendritic cells. Macrophages ingest particulate antigens such as bacteria and are induced by infectious agents or other appropriate stimuli to express MHC molecules. The unique ability of B cells to bind and internalize soluble protein antigens via their receptors may also be important to induce T cells. Presenting the antigen on MHC molecules leads to activation of T cells which induces their proliferation and differentiation into armed effector T cells. The most important function of effector T cells is the killing of infected cells by CD8+ cytotoxic T cells and the activation of macrophages by Th1 cells which together make up cell-mediated immunity, and the activation of B cells by both Th2 and Th1 cells to produce different classes of antibody, thus driving the humoral immune response. T cells recognize an antigen by their T cell receptors which do not recognize and bind antigen directly, but instead recognize short peptide fragments e.g. of pathogen-derived protein antigens, which are bound to MHC molecules on the surfaces of other cells.

Cellular Immunity/Cellular Immune Response:

Cellular immunity relates typically to the activation of macrophages, natural killer cells (NK), antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. In a more general way, cellular immunity is not related to antibodies but to the activation of cells of the immune system. A cellular immune response is characterized e.g. by activating antigen-specific cytotoxic T-lymphocytes that are able to induce apoptosis in body cells displaying epitopes of an antigen on their surface, such as virus-infected cells, cells with intracellular bacteria, and cancer cells displaying tumor antigens; activating macrophages and natural killer cells, enabling them to destroy pathogens; and stimulating cells to secrete a variety of cytokines that influence the function of other cells involved in adaptive immune responses and innate immune responses.

Humoral Immunity/Humoral Immune Response:

Humoral immunity refers typically to antibody production and the accessory processes that may accompany it. A humoral immune response may be typically characterized, e.g., by Th2 activation and cytokine production, germinal center formation and isotype switching, affinity maturation and memory cell generation. Humoral immunity also typically may refer to the effector functions of antibodies, which include pathogen and toxin neutralization, classical complement activation, and opsonin promotion of phagocytosis and pathogen elimination.

Innate Immune System:

The innate immune system, also known as non-specific immune system, comprises the cells and mechanisms that defend the host from infection by other organisms in a non-specific manner. This means that the cells of the innate system recognize and respond to pathogens in a generic way, but unlike the adaptive immune system, it does not confer long-lasting or protective immunity to the host. The innate immune system may be e.g. activated by ligands of pathogen-associated molecular patterns (PAMP) receptors, e.g. Toll-like receptors (TLRs) or other auxiliary substances such as lipopolysaccharides, TNF-alpha, CD40 ligand, or cytokines, monokines, lymphokines, interleukins or chemokines, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-14, IL-15, IL-16, IL-17, IL-18, IL-19, IL-20, IL-21, IL-22, IL-23, IL-24, IL-25, IL-26, IL-27, IL-28, IL-29, IL-30, IL-31, IL-32, IL-33, IFN-alpha, IFN-beta, IFN-gamma, GM-CSF, G-CSF, M-CSF, LT-beta, TNF-alpha, growth factors, and hGH, a ligand of human Toll-like receptor TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, a ligand of murine Toll-like receptor TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12 or TLR13, a ligand of a NOD-like receptor, a ligand of a RIG-I like receptor, an immunostimulatory nucleic acid, an immunostimulatory RNA (isRNA), a CpG-DNA, an antibacterial agent, or an anti-viral agent. Typically a response of the innate immune system includes recruiting immune cells to sites of infection, through the production of chemical factors, including specialized chemical mediators, called cytokines; activation of the complement cascade; identification and removal of foreign substances present in organs, tissues, the blood and lymph, by specialized white blood cells; activation of the adaptive immune system through a process known as antigen presentation; and/or acting as a physical and chemical barrier to infectious agents.

Adjuvant/Adjuvant Component:

An adjuvant or an adjuvant component in the broadest sense is typically a (e.g. pharmacological or immunological) agent or composition that may modify, e.g. enhance, the efficacy of other agents, such as a drug or vaccine. Conventionally the term refers in the context of the invention to a compound or composition that serves as a carrier or auxiliary substance for immunogens and/or other pharmaceutically active compounds. It is to be interpreted in a broad sense and refers to a broad spectrum of substances that are able to increase the immunogenicity of antigens incorporated into or co-administered with an adjuvant in question. In the context of the present invention an adjuvant will preferably enhance the specific immunogenic effect of the active agents of the present invention. Typically, “adjuvant” or “adjuvant component” has the same meaning and can be used mutually. Adjuvants may be divided, e.g., into immuno potentiators, antigenic delivery systems or even combinations thereof.

The term “adjuvant” is typically understood not to comprise agents which confer immunity by themselves. An adjuvant assists the immune system unspecifically to enhance the antigen-specific immune response by e.g. promoting presentation of an antigen to the immune system or induction of an unspecific innate immune response. Furthermore, an adjuvant may preferably e.g. modulate the antigen-specific immune response by e.g. shifting the dominating Th2-based antigen specific response to a more Th1-based antigen specific response or vice versa. Accordingly, an adjuvant may favourably modulate cytokine expression/secretion, antigen presentation, type of immune response etc.

Immunostimulatory RNA:

An immunostimulatory RNA (isRNA) in the context of the invention may typically be a RNA that is able to induce an innate immune response itself. It usually does not have an open reading frame and thus does not provide a peptide-antigen or immunogen but elicits an innate immune response e.g. by binding to a specific kind of Toll-like-receptor (TLR) or other suitable receptors. However, of course also mRNAs having an open reading frame and coding for a peptide/protein (e.g. an antigenic function) may induce an innate immune response.

Antigen:

According to the present invention, the term “antigen” refers typically to a substance which may be recognized by the immune system and may be capable of triggering an antigen-specific immune response, e.g. by formation of antibodies or antigen-specific T-cells as part of an adaptive immune response. An antigen may be a protein or peptide. In this context, the first step of an adaptive immune response is the activation of naïve antigen-specific T cells by antigen-presenting cells. This occurs in the lymphoid tissues and organs through which naïve T cells are constantly passing. The three cell types that can serve as antigen-presenting cells are dendritic cells, macrophages, and B cells. Each of these cells has a distinct function in eliciting immune responses. Tissue dendritic cells take up antigens by phagocytosis and macropinocytosis and are stimulated by infection to migrate to the local lymphoid tissue, where they differentiate into mature dendritic cells. Macrophages ingest particulate antigens such as bacteria and are induced by infectious agents to express MHC class II molecules. The unique ability of B cells to bind and internalize soluble protein antigens via their receptors may be important to induce T cells. By presenting the antigen on MHC molecules leads to activation of T cells which induces their proliferation and differentiation into armed effector T cells. The most important function of effector T cells is the killing of infected cells by CD8⁺ cytotoxic T cells and the activation of macrophages by TH1 cells which together make up cell-mediated immunity, and the activation of B cells by both TH2 and TH1 cells to produce different classes of antibody, thus driving the humoral immune response. T cells recognize an antigen by their T cell receptors which does not recognize and bind antigen directly, but instead recognize short peptide fragments e.g. of pathogens' protein antigens, which are bound to MHC molecules on the surfaces of other cells.

T cells fall into two major classes that have different effector functions. The two classes are distinguished by the expression of the cell-surface proteins CD4 and CD8. These two types of T cells differ in the class of MHC molecule that they recognize. There are two classes of MHC molecules—MHC class I and MHC class II molecules—which differ in their structure and expression pattern on tissues of the body. CD4⁺ T cells bind to a MHC class II molecule and CD8⁺ T cells to a MHC class I molecule. MHC class I and MHC class II molecules have distinct distributions among cells that reflect the different effector functions of the T cells that recognize them. MHC class I molecules present peptides of cytosolic and nuclear origin e.g. from pathogens, commonly viruses, to CD8⁺ T cells, which differentiate into cytotoxic T cells that are specialized to kill any cell that they specifically recognize. Almost all cells express MHC class I molecules, although the level of constitutive expression varies from one cell type to the next. But not only pathogenic peptides from viruses are presented by MHC class I molecules, also self-antigens like tumour antigens are presented by them. MHC class I molecules bind peptides from proteins degraded in the cytosol and transported in the endoplasmic reticulum. The CD8⁺ T cells that recognize MHC class I:peptide complexes at the surface of infected cells are specialized to kill any cells displaying foreign peptides and so rid the body of cells infected with viruses and other cytosolic pathogens. The main function of CD4⁺ T cells (CD4⁺ helper T cells) that recognize MHC class II molecules is to activate other effector cells of the immune system. Thus MHC class II molecules are normally found on B lymphocytes, dendritic cells, and macrophages, cells that participate in immune responses, but not on other tissue cells. Macrophages, for example, are activated to kill the intravesicular pathogens they harbour, and B cells to secrete immunoglobulins against foreign molecules. MHC class II molecules are prevented from binding to peptides in the endoplasmic reticulum and thus MHC class II molecules bind peptides from proteins which are degraded in endosomes. They can capture peptides from pathogens that have entered the vesicular system of macrophages, or from antigens internalized by immature dendritic cells or the immunoglobulin receptors of B cells. Pathogens that accumulate in large numbers inside macrophage and dendritic cell vesicles tend to stimulate the differentiation of TH1 cells, whereas extracellular antigens tend to stimulate the production of TH2 cells. TH1 cells activate the microbicidal properties of macrophages and induce B cells to make IgG antibodies that are very effective of opsonising extracellular pathogens for ingestion by phagocytic cells, whereas TH2 cells initiate the humoral response by activating naïve B cells to secrete IgM, and induce the production of weakly opsonising antibodies such as IgG1 and IgG3 (mouse) and IgG2 and IgG4 (human) as well as IgA and IgE (mouse and human).

Epitope (also called “antigen determinant”):

T cell epitopes or parts of the proteins in the context of the present invention may comprise fragments preferably having a length of about 6 to about 20 or even more amino acids, e.g. fragments as processed and presented by MHC class I molecules, preferably having a length of about 8 to about 10 amino acids, e.g. 8, 9, or 10, (or even 11, or 12 amino acids), or fragments as processed and presented by MHC class II molecules, preferably having a length of about 13 or more amino acids, e.g. 13, 14, 15, 16, 17, 18, 19, 20 or even more amino acids, wherein these fragments may be selected from any part of the amino acid sequence. These fragments are typically recognized by T cells in form of a complex consisting of the peptide fragment and an MHC molecule.

B cell epitopes are typically fragments located on the outer surface of (native) protein or peptide antigens as defined herein, preferably having 5 to 15 amino acids, more preferably having 5 to 12 amino acids, even more preferably having 6 to 9 amino acids, which may be recognized by antibodies, i.e. in their native form.

Such epitopes of proteins or peptides may furthermore be selected from any of the herein mentioned variants of such proteins or peptides. In this context antigenic determinants can be conformational or discontinuous epitopes which are composed of segments of the proteins or peptides as defined herein that are discontinuous in the amino acid sequence of the proteins or peptides as defined herein but are brought together in the three-dimensional structure or continuous or linear epitopes which are composed of a single polypeptide chain.

Vaccine:

A vaccine is typically understood to be a prophylactic or therapeutic material providing at least one antigen or antigenic function. The antigen or antigenic function may stimulate the body's adaptive immune system to provide an adaptive immune response.

Antigen-Providing mRNA:

An antigen-providing mRNA in the context of the invention may typically be an mRNA, having at least one open reading frame that can be translated by a cell or an organism provided with that mRNA. The product of this translation is a peptide or protein that may act as an antigen, preferably as an immunogen. The product may also be a fusion protein composed of more than one immunogen, e.g. a fusion protein that consist of two or more epitopes, peptides or proteins derived from the same or different virus-proteins, wherein the epitopes, peptides or proteins may be linked by linker sequences.

Bi-/Multicistronic mRNA:

mRNA, that typically may have two (bicistronic) or more (multicistronic) open reading frames (ORF). An open reading frame in this context is a sequence of several nucleotide triplets (codons) that can be translated into a peptide or protein. Translation of such a mRNA yields two (bicistronic) or more (multicistronic) distinct translation products (provided the ORFs are not identical). For expression in eukaryotes such mRNAs may for example comprise an internal ribosomal entry site (IRES) sequence.

5′-CAP-Structure:

A 5′-CAP is typically a modified nucleotide, particularly a guanine nucleotide, added to the 5′ end of an mRNA-molecule. Preferably, the 5′-CAP is added using a 5′-5′-triphosphate linkage (also named m7GpppN). Further examples of 5′-CAP structures include glyceryl, inverted deoxy abasic residue (moiety), 4′,5′ methylene nucleotide, 1-(beta-D-erythrofuranosyl) nucleotide, 4′-thio nucleotide, carbocyclic nucleotide, 1,5-anhydrohexitol nucleotide, L-nucleotides, alpha-nucleotide, modified base nucleotide, threo-pentofuranosyl nucleotide, acyclic 3′,4′-seco nucleotide, acyclic 3,4-dihydroxybutyl nucleotide, acyclic 3,5 dihydroxypentyl nucleotide, 3′-3′-inverted nucleotide moiety, 3′-3′-inverted abasic moiety, 3′-2′-inverted nucleotide moiety, 3′-2′-inverted abasic moiety, 1,4-butanediol phosphate, 3′-phosphoramidate, hexylphosphate, aminohexyl phosphate, 3′-phosphate, 3′phosphorothioate, phosphorodithioate, or bridging or non-bridging methylphosphonate moiety. These modified 5′-CAP structures may be used in the context of the present invention to modify the inventive mRNA sequence. Further modified 5′-CAP structures which may be used in the context of the present invention are CAP1 (methylation of the ribose of the adjacent nucleotide of m7GpppN), CAP2 (methylation of the ribose of the 2^(nd) nucleotide downstream of the m7GpppN), CAP3 (methylation of the ribose of the 3^(rd) nucleotide downstream of the m7GpppN), CAP4 (methylation of the ribose of the 4^(th) nucleotide downstream of the m7GpppN), ARCA (anti-reverse CAP analogue, modified ARCA (e.g. phosphothioate modified ARCA), inosine, N1-methyl-guanosine, 2′-fluoro-guanosine, 7-deaza-guanosine, 8-oxo-guanosine, 2-amino-guanosine, LNA-guanosine, and 2-azido-guanosine.

Fragments of Proteins:

“Fragments” of proteins or peptides in the context of the present invention may, typically, comprise a sequence of a protein or peptide as defined herein, which is, with regard to its amino acid sequence (or its encoded nucleic acid molecule), N-terminally and/or C-terminally truncated compared to the amino acid sequence of the original (native) protein (or its encoded nucleic acid molecule). Such truncation may thus occur either on the amino acid level or correspondingly on the nucleic acid level. A sequence identity with respect to such a fragment as defined herein may therefore preferably refer to the entire protein or peptide as defined herein or to the entire (coding) nucleic acid molecule of such a protein or peptide.

Fragments of proteins or peptides in the context of the present invention may furthermore comprise a sequence of a protein or peptide as defined herein, which has a length of for example at least 5 amino acids, preferably a length of at least 6 amino acids, preferably at least 7 amino acids, more preferably at least 8 amino acids, even more preferably at least 9 amino acids; even more preferably at least 10 amino acids; even more preferably at least 11 amino acids; even more preferably at least 12 amino acids; even more preferably at least 13 amino acids; even more preferably at least 14 amino acids; even more preferably at least 15 amino acids; even more preferably at least 16 amino acids; even more preferably at least 17 amino acids; even more preferably at least 18 amino acids; even more preferably at least 19 amino acids; even more preferably at least 20 amino acids; even more preferably at least 25 amino acids; even more preferably at least 30 amino acids; even more preferably at least 35 amino acids; even more preferably at least 50 amino acids; or most preferably at least 100 amino acids. For example such fragment may have a length of about 6 to about 20 or even more amino acids, e.g. fragments as processed and presented by MHC class I molecules, preferably having a length of about 8 to about 10 amino acids, e.g. 8, 9, or 10, (or even 6, 7, 11, or 12 amino acids), or fragments as processed and presented by MHC class II molecules, preferably having a length of about 13 or more amino acids, e.g. 13, 14, 15, 16, 17, 18, 19, 20 or even more amino acids, wherein these fragments may be selected from any part of the amino acid sequence. These fragments are typically recognized by T-cells in form of a complex consisting of the peptide fragment and an MHC molecule, i.e. the fragments are typically not recognized in their native form. Fragments of proteins or peptides may comprise at least one epitope of those proteins or peptides. Furthermore also domains of a protein, like the extracellular domain, the intracellular domain or the transmembrane domain and shortened or truncated versions of a protein may be understood to comprise a fragment of a protein.

Variants of Proteins:

“Variants” of proteins or peptides as defined in the context of the present invention may be generated, having an amino acid sequence which differs from the original sequence in one or more mutation(s), such as one or more substituted, inserted and/or deleted amino acid(s). Preferably, these fragments and/or variants have the same biological function or specific activity compared to the full-length native protein, e.g. its specific antigenic property. “Variants” of proteins or peptides as defined in the context of the present invention may comprise conservative amino acid substitution(s) compared to their native, i.e. non-mutated physiological, sequence. Those amino acid sequences as well as their encoding nucleotide sequences in particular fall under the term variants as defined herein. Substitutions in which amino acids, which originate from the same class, are exchanged for one another are called conservative substitutions. In particular, these are amino acids having aliphatic side chains, positively or negatively charged side chains, aromatic groups in the side chains or amino acids, the side chains of which can enter into hydrogen bridges, e.g. side chains which have a hydroxyl function. This means that e.g. an amino acid having a polar side chain is replaced by another amino acid having a likewise polar side chain, or, for example, an amino acid characterized by a hydrophobic side chain is substituted by another amino acid having a likewise hydrophobic side chain (e.g. serine (threonine) by threonine (serine) or leucine (isoleucine) by isoleucine (leucine)). Insertions and substitutions are possible, in particular, at those sequence positions which cause no modification to the three-dimensional structure or do not affect the binding region. Modifications to a three-dimensional structure by insertion(s) or deletion(s) can easily be determined e.g. using CD spectra (circular dichroism spectra) (Urry, 1985, Absorption, Circular Dichroism and ORD of Polypeptides, in: Modern Physical Methods in Biochemistry, Neuberger et al. (ed.), Elsevier, Amsterdam).

A “variant” of a protein or peptide may have at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% amino acid identity over a stretch of 10, 20, 30, 50, 75 or 100 amino acids of such protein or peptide.

Furthermore, variants of proteins or peptides as defined herein, which may be encoded by a nucleic acid molecule, may also comprise those sequences, wherein nucleotides of the encoding nucleic acid sequence are exchanged according to the degeneration of the genetic code, without leading to an alteration of the respective amino acid sequence of the protein or peptide, i.e. the amino acid sequence or at least part thereof may not differ from the original sequence in one or more mutation(s) within the above meaning.

Identity of a Sequence:

In order to determine the percentage to which two sequences are identical, e.g. nucleic acid sequences or amino acid sequences as defined herein, preferably the amino acid sequences encoded by a nucleic acid sequence of the polymeric carrier as defined herein or the amino acid sequences themselves, the sequences can be aligned in order to be subsequently compared to one another. Therefore, e.g. a position of a first sequence may be compared with the corresponding position of the second sequence. If a position in the first sequence is occupied by the same component (residue) as is the case at a position in the second sequence, the two sequences are identical at this position. If this is not the case, the sequences differ at this position. If insertions occur in the second sequence in comparison to the first sequence, gaps can be inserted into the first sequence to allow a further alignment. If deletions occur in the second sequence in comparison to the first sequence, gaps can be inserted into the second sequence to allow a further alignment. The percentage to which two sequences are identical is then a function of the number of identical positions divided by the total number of positions including those positions which are only occupied in one sequence. The percentage to which two sequences are identical can be determined using a mathematical algorithm. A preferred, but not limiting, example of a mathematical algorithm which can be used is the algorithm of Karlin et al. (1993), PNAS USA, 90:5873-5877 or Altschul et al. (1997), Nucleic Acids Res., 25:3389-3402. Such an algorithm is integrated in the BLAST program. Sequences which are identical to the sequences of the present invention to a certain extent can be identified by this program.

Derivative of a Protein or Peptide:

A derivative of a peptide or protein is typically understood to be a molecule that is derived from another molecule, such as said peptide or protein. A “derivative” of a peptide or protein also encompasses fusions comprising a peptide or protein used in the present invention. For example, the fusion comprises a label, such as, for example, an epitope, e.g., a FLAG epitope or a V5 epitope. For example, the epitope is a FLAG epitope. Such a tag is useful for, for example, purifying the fusion protein.

Monocistronic mRNA:

A monocistronic mRNA may typically be an mRNA, that encodes only one open reading frame. An open reading frame in this context is a sequence of several nucleotide triplets (codons) that can be translated into a peptide or protein.

Nucleic Acid:

The term nucleic acid means any DNA- or RNA-molecule and is used synonymous with polynucleotide. Wherever herein reference is made to a nucleic acid or nucleic acid sequence encoding a particular protein and/or peptide, said nucleic acid or nucleic acid sequence, respectively, preferably also comprises regulatory sequences allowing in a suitable host, e.g. a human being, its expression, i.e. transcription and/or translation of the nucleic acid sequence encoding the particular protein or peptide.

Peptide:

A peptide is a polymer of amino acid monomers. Usually the monomers are linked by peptide bonds. The term “peptide” does not limit the length of the polymer chain of amino acids. In some embodiments of the present invention a peptide may for example contain less than 50 monomer units. Longer peptides are also called polypeptides, typically having 50 to 600 monomeric units, more specifically 50 to 300 monomeric units.

Pharmaceutically Effective Amount:

A pharmaceutically effective amount in the context of the invention is typically understood to be an amount that is sufficient to induce an immune response.

Protein:

A protein typically consists of one or more peptides and/or polypeptides folded into 3-dimensional form, facilitating a biological function.

Poly (C) Sequence:

A poly-(C)-sequence is typically a long sequence of cytosine nucleotides, typically about 10 to about 200 cytosine nucleotides, preferably about 10 to about 100 cytosine nucleotides, more preferably about 10 to about 70 cytosine nucleotides or even more preferably about 20 to about 50 or even about 20 to about 30 cytosine nucleotides. A poly(C) sequence may preferably be located 3′ of the coding region comprised by a nucleic acid.

Poly-A-Tail:

A poly-A-tail also called “3′-poly(A) tail” is typically a long sequence of adenosine nucleotides of up to about 400 adenosine nucleotides, e.g. from about 25 to about 400, preferably from about 50 to about 400, more preferably from about 50 to about 300, even more preferably from about 50 to about 250, most preferably from about 60 to about 250 adenosine nucleotides, added to the 3′ end of a RNA.

Stabilized Nucleic Acid:

A stabilized nucleic acid, typically, exhibits a modification increasing resistance to in vivo degradation (e.g. degradation by an exo- or endo-nuclease) and/or ex vivo degradation (e.g. by the manufacturing process prior to vaccine administration, e.g. in the course of the preparation of the vaccine solution to be administered). Stabilization of RNA can, e.g., be achieved by providing a 5′-CAP-Structure, a Poly-A-Tail, or any other UTR-modification. It can also be achieved by backbone-modification or modification of the G/C-content of the nucleic acid. Various other methods are known in the art and conceivable in the context of the invention.

Carrier/Polymeric Carrier:

A carrier in the context of the invention may typically be a compound that facilitates transport and/or complexation of another compound. Said carrier may form a complex with said other compound. A polymeric carrier is a carrier that is formed of a polymer.

Cationic Component:

The term “cationic component” typically refers to a charged molecule, which is positively charged (cation) at a pH value of typically about 1 to 9, preferably of a pH value of or below 9 (e.g. 5 to 9), of or below 8 (e.g. 5 to 8), of or below 7 (e.g. 5 to 7), most preferably at physiological pH values, e.g. about 7.3 to 7.4. Accordingly, a cationic peptide, protein or polymer according to the present invention is positively charged under physiological conditions, particularly under physiological salt conditions of the cell in vivo. A cationic peptide or protein preferably contains a larger number of cationic amino acids, e.g. a larger number of Arg, His, Lys or Orn than other amino acid residues (in particular more cationic amino acids than anionic amino acid residues like Asp or Glu) or contains blocks predominantly formed by cationic amino acid residues. The definition “cationic” may also refer to “polycationic” components.

Vehicle:

An agent, e.g. a carrier, that may typically be used within a pharmaceutical composition or vaccine for facilitating administering of the components of the pharmaceutical composition or vaccine to an individual.

3′-Untranslated Region (3′UTR):

A 3′UTR is typically the part of an mRNA which is located between the protein coding region (i.e. the open reading frame) and the poly(A) sequence of the mRNA. A 3′UTR of the mRNA is not translated into an amino acid sequence. The 3′UTR sequence is generally encoded by the gene which is transcribed into the respective mRNA during the gene expression process. The genomic sequence is first transcribed into pre-mature mRNA, which comprises optional introns. The pre-mature mRNA is then further processed into mature mRNA in a maturation process. This maturation process comprises the steps of 5′-Capping, splicing the pre-mature mRNA to excise optional introns and modifications of the 3′-end, such as polyadenylation of the 3′-end of the pre-mature mRNA and optional endo- or exonuclease cleavages etc. In the context of the present invention, a 3′UTR corresponds to the sequence of a mature mRNA which is located 3′ to the stop codon of the protein coding region, preferably immediately 3′ to the stop codon of the protein coding region, and which extends to the 5′-side of the poly(A) sequence, preferably to the nucleotide immediately 5′ to the poly(A) sequence. The term “corresponds to” means that the 3′UTR sequence may be an RNA sequence, such as in the mRNA sequence used for defining the 3′UTR sequence, or a DNA sequence which corresponds to such RNA sequence. In the context of the present invention, the term “a 3′UTR of a gene”, such as “a 3′UTR of an albumin gene”, is the sequence which corresponds to the 3′UTR of the mature mRNA derived from this gene, i.e. the mRNA obtained by transcription of the gene and maturation of the pre-mature mRNA. The term “3′UTR of a gene” encompasses the DNA sequence and the RNA sequence of the 3′UTR.

5′-Untranslated Region (5′UTR):

A 5′-UTR is typically understood to be a particular section of messenger RNA (mRNA). It is located 5′ of the open reading frame of the mRNA. Typically, the 5′UTR starts with the transcriptional start site and ends one nucleotide before the start codon of the open reading frame. The 5′-UTR may comprise elements for controlling gene expression, also called regulatory elements. Such regulatory elements may be, for example, ribosomal binding sites or a 5′-Terminal Oligopyrimidine Tract. The 5′UTR may be posttranscriptionally modified, for example by addition of a 5′-CAP. In the context of the present invention, a 5′UTR corresponds to the sequence of a mature mRNA which is located between the 5′-CAP and the start codon. Preferably, the 5′UTR corresponds to the sequence which extends from a nucleotide located 3′ to the 5′-CAP, preferably from the nucleotide located immediately 3′ to the 5′-CAP, to a nucleotide located 5′ to the start codon of the protein coding region, preferably to the nucleotide located immediately 5′ to the start codon of the protein coding region. The nucleotide located immediately 3′ to the 5′-CAP of a mature mRNA typically corresponds to the transcriptional start site. The term “corresponds to” means that the 5′UTR sequence may be an RNA sequence, such as in the mRNA sequence used for defining the 5′UTR sequence, or a DNA sequence which corresponds to such RNA sequence. In the context of the present invention, the term “a 5′UTR of a gene”, such as “a 5′UTR of a TOP gene”, is the sequence which corresponds to the 5′UTR of the mature mRNA derived from this gene, i.e. the mRNA obtained by transcription of the gene and maturation of the pre-mature mRNA. The term “5′UTR of a gene” encompasses the DNA sequence and the RNA sequence of the 5′UTR.

5′Terminal Oligopyrimidine Tract (TOP):

The 5′terminal oligopyrimidine tract (TOP) is typically a stretch of pyrimidine nucleotides located at the 5′ terminal region of a nucleic acid molecule, such as the 5′ terminal region of certain mRNA molecules or the 5′ terminal region of a functional entity, e.g. the transcribed region, of certain genes. The sequence starts with a cytidine, which usually corresponds to the transcriptional start site, and is followed by a stretch of usually about 3 to 30 pyrimidine nucleotides. For example, the TOP may comprise 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or even more nucleotides. The pyrimidine stretch and thus the 5′ TOP ends one nucleotide 5′ to the first purine nucleotide located downstream of the TOP. Messenger RNA that contains a 5′terminal oligopyrimidine tract is often referred to as TOP mRNA. Accordingly, genes that provide such messenger RNAs are referred to as TOP genes. TOP sequences have, for example, been found in genes and mRNAs encoding peptide elongation factors and ribosomal proteins.

TOP Motif:

In the context of the present invention, a TOP motif is a nucleic acid sequence which corresponds to a 5′TOP as defined above. Thus, a TOP motif in the context of the present invention is preferably a stretch of pyrimidine nucleotides having a length of 3-30 nucleotides. Preferably, the TOP-motif consists of at least 3 pyrimidine nucleotides, preferably at least 4 pyrimidine nucleotides, preferably at least 5 pyrimidine nucleotides, more preferably at least 6 nucleotides, more preferably at least 7 nucleotides, most preferably at least 8 pyrimidine nucleotides, wherein the stretch of pyrimidine nucleotides preferably starts at its 5′end with a cytosine nucleotide. In TOP genes and TOP mRNAs, the TOP-motif preferably starts at its 5′end with the transcriptional start site and ends one nucleotide 5′ to the first purin residue in said gene or mRNA. A TOP motif in the sense of the present invention is preferably located at the 5′ end of a sequence which represents a 5′UTR or at the 5′end of a sequence which codes for a 5′UTR. Thus, preferably, a stretch of 3 or more pyrimidine nucleotides is called “TOP motif” in the sense of the present invention if this stretch is located at the 5′ end of a respective sequence, such as the inventive mRNA, the 5′UTR element of the inventive mRNA, or the nucleic acid sequence which is derived from the 5′UTR of a TOP gene as described herein. In other words, a stretch of 3 or more pyrimidine nucleotides which is not located at the 5′-end of a 5′UTR or a 5′UTR element but anywhere within a 5′UTR or a 5′UTR element is preferably not referred to as “TOP motif”.

TOP Gene:

TOP genes are typically characterised by the presence of a 5′ terminal oligopyrimidine tract. Furthermore, most TOP genes are characterized by a growth-associated translational regulation. However, also TOP genes with a tissue specific translational regulation are known. As defined above, the 5′UTR of a TOP gene corresponds to the sequence of a 5′UTR of a mature mRNA derived from a TOP gene, which preferably extends from the nucleotide located 3′ to the 5′-CAP to the nucleotide located 5′ to the start codon. A 5′UTR of a TOP gene typically does not comprise any start codons, preferably no upstream AUGs (uAUGs) or upstream open reading frames (uORFs). Therein, upstream AUGs and upstream open reading frames are typically understood to be AUGs and open reading frames that occur 5′ of the start codon (AUG) of the open reading frame that should be translated. The 5′UTRs of TOP genes are generally rather short. The lengths of 5′UTRs of TOP genes may vary between 20 nucleotides up to 500 nucleotides, and are typically less than about 200 nucleotides, preferably less than about 150 nucleotides, more preferably less than about 100 nucleotides. Exemplary 5′UTRs of TOP genes in the sense of the present invention are the nucleic acid sequences extending from the nucleotide at position 5 to the nucleotide located immediately 5′ to the start codon (e.g. the ATG) in the sequences according to SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 14221-1363 of the patent application PCT/EP2012/002448WO2013/143700 or homologs or variants thereof, whose disclosure is incorporated herewith by reference. In this context a particularly preferred fragment of a 5′UTR of a TOP gene is a 5′UTR of a TOP gene lacking the 5′TOP motif. The term ‘5′UTR of a TOP gene’ preferably refers to the 5′UTR of a naturally occurring TOP gene.

Fragment of a Nucleic Acid Sequence, Particularly an mRNA:

A fragment of a nucleic acid sequence consists of a continuous stretch of nucleotides corresponding to a continuous stretch of nucleotides in the full-length nucleic acid sequence which is the basis for the nucleic acid sequence of the fragment, which represents at least 20%, preferably at least 30%, more preferably at least 40%, more preferably at least 50%, even more preferably at least 60%, even more preferably at least 70%, even more preferably at least 80%, and most preferably at least 90% of the full-length nucleic acid sequence. Such a fragment, in the sense of the present invention, is preferably a functional fragment of the full-length nucleic acid sequence.

Variant of a Nucleic Acid Sequence, Particularly an mRNA:

A variant of a nucleic acid sequence refers to a variant of nucleic acid sequences which forms the basis of a nucleic acid sequence. For example, a variant nucleic acid sequence may exhibit one or more nucleotide deletions, insertions, additions and/or substitutions compared to the nucleic acid sequence from which the variant is derived. Preferably, a variant of a nucleic acid sequence is at least 40%, preferably at least 50%, more preferably at least 60%, more preferably at least 70%, even more preferably at least 80%, even more preferably at least 90%, most preferably at least 95% identical to the nucleic acid sequence the variant is derived from. Preferably, the variant is a functional variant. A “variant” of a nucleic acid sequence may have at least 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99% nucleotide identity over a stretch of 10, 20, 30, 50, 75 or 100 nucleotide of such nucleic acid sequence.

Homolog of a Nucleic Acid Sequence:

The term “homolog” of a nucleic acid sequence refers to sequences of other species than the particular sequence. It is particular preferred that the nucleic acid sequence is of human origin and therefore it is preferred that the homolog is a homolog of a human nucleic acid sequence.

Jet injection: The term “jet injection”, as used herein, refers to a needle-free injection method, wherein a fluid containing at least one inventive mRNA sequence and, optionally, further suitable excipients is forced through an orifice, thus generating an ultra-fine liquid stream of high pressure that is capable of penetrating mammalian skin and, depending on the injection settings, subcutaneous tissue or muscle tissue. In principle, the liquid stream forms a hole in the skin, through which the liquid stream is pushed into the target tissue. Preferably, jet injection is used for intradermal, subcutaneous or intramuscular injection of the mRNA sequence according to the invention. In a preferred embodiment, jet injection is used for intramuscular injection of the inventive mRNA. In a further preferred embodiment, jet injection is used for intradermal injection of the inventive mRNa.

The present invention is based on the surprising finding of the present inventors that an mRNA sequence comprising a coding region, encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) induces antigen-specific immune responses and therefore prevent or at least minimize Respiratory syncytial virus (RSV) infections. It was very surprising for the inventors that the inventive mRNA sequence induces at least the same immune responses than vaccines based on inactivated RSV which consists of the whole virus. Even more surprisingly the inventive mRNA sequence coding for an antigenic protein of RSV induced antigen-specific CD8+-T cells in contrast to a vaccine based on an inactivated RSV. Additionally, in a cotton rat RSV challenge model, the virus titers in the nose and in the lung of mRNA vaccinated animals were much lower compared to animals vaccinated with vaccines based on an inactivated RSV virus. With regard to safety the inventors could show that the mRNA-based RSV vaccine showed no hints for vaccine-mediated disease enhancement, in terms of lung pathology, compared to a vaccine based on formalin-inactivated virus. Furthermore, it has surprisingly been found by the inventors that already one single vaccination with the inventive mRNA sequence was sufficient for eliciting an immune response against the administered antigen(s). Specifically, it has been found that one single administration, preferably by intradermal or intramuscular injection, of the inventive mRNA is highly efficient in reducing viral titers in the lung after challenge with RSV virus.

In summary, the inventive mRNA sequence comprising a coding region encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) could provide an effective and safe vaccine, particularly for infants, the elderly and immunocompromised patients.

In this context it is particularly preferred that the inventive mRNA sequence comprises a coding region, encoding at least one antigenic peptide or protein derived from the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof.

The coding region of the inventive mRNA sequence according to the first aspect of the present invention may occur as a mono-, bi-, or even multicistronic mRNA, i.e. an mRNA sequence which carries the coding sequences of one, two or more proteins or peptides. Such coding sequences in bi-, or even multicistronic mRNAs may be separated by at least one internal ribosome entry site (IRES) sequence, e.g. as described herein or by signal peptides which induce the cleavage of the resulting polypeptide which comprises several proteins or peptides.

According to the first aspect of the present invention, the inventive mRNA sequence comprises a coding region, encoding at least one antigenic peptide or protein derived from the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof. In a particularly preferred embodiment of the first aspect of the invention, the inventive mRNA sequence comprises a coding region, encoding at least one antigenic peptide or protein derived from the fusion protein F, the nucleoprotein N, or the M2-1 protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof.

In this context, the amino acid sequence of the at least one antigenic peptide or protein may be selected from any peptide or protein derived from the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of any RSV isolate or from any synthetically engineered RSV peptide or protein or from a fragment, variant or derivative thereof.

In a particularly preferred embodiment, the full-length protein of the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV) is encoded by the coding region comprised in the inventive mRNA.

In this context, the full-length protein from the fusion protein F and the nucleoprotein N are particularly preferred. Furthermore a mutant of the F protein with a deletion of the cytoplasmic tail is particularly preferred. An example of such a deletion mutant is the RSV-Fdel 554-574 long protein according to (Oomens et al. 2006. J. Virol. 80(21):10465-77).

In a further particularly preferred embodiment, a fragment comprising at least one epitope of the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV) is encoded by the coding region comprised in the inventive mRNA.

Particularly preferred are the amino acid sequences of the RSV strain long (ATCC VR-26) according to the NCBI accession No. AY911262:

Fusion protein F of the RSV strain ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 1: MELPILKANA ITTILAAVTF CFASSQNITE EFYQSTCSAV  SKGYLSALRT GWYTSVITIE LSNIKENKCN GTDAKVKLIN  QELDKYKNAV TELQLLMQST TAANNRARRE LPRFMNYTLN  NTKKTNVTLS KKRKRRFLGF LLGVGSAIAS GIAVSKVLHL EGEVNKIKSA LLSTNKAVVS LSNGVSVLTS KVLDLKNYID  KQLLPIVNKQ SCRISNIETV IEFQQKNNRL LEITREFSVN  AGVTTPVSTY MLTNSELLSL INDMPITNDQ KKLMSNNVQI  VRQQSYSIMS IIKEEVLAYV VQLPLYGVID TPCWKLHTSP LCTTNTKEGS NICLTRTDRG WYCDNAGSVS FFPQAETCKV  QSNRVFCDTM NSLTLPSEVN LCNVDIFNPK YDCKIMTSKT  DVSSSVITSL GAIVSCYGKT KCTASNKNRG IIKTFSNGCD  YVSNKGVDTV SVGNTLYYVN KQEGKSLYVK GEPIINFYDP  LVFPSDEFDA SISQVNEKIN QSLAFIRKSD ELLHHVNAGK  STTNIMITTI IIVIIVILLS LIAVGLLLYC KARSTPVTLS KDQLSGINNI AFSN Glycoprotein G of the RSV strain ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 2: MSKNKDQRTA KTLEKTWDTL NHLLFISSGL YKLNLKSIAQ  ITLSILAMII STSLIITAII FIASANHKVT LTTAIIQDAT  SQIKNTTPTY LTQDPQLGIS FSNLSEITSQ TTTILASTTP GVKSNLQPTT VKTKNTTTTQ TQPSKPTTKQ RQNKPPNKPN  NDFHFEVFNF VPCSICSNNP TCWAICKRIP NKKPGKKTTT  KPTKKPTFKT TKKDLKPQTT KPKEVPTTKP TEEPTINTTK  TNITTTLLTN NTTGNPKLTS QMETFHSTSS EGNLSPSQVS TTSEHPSQPS SPPNTTRQ Short hydrophobic protein SH of the RSV strain  ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 3: MENTSITIEF SSKFWPYFTL IHMITTIISL LIIISIMTAI  LNKLCEYNVF HNKTFELPRA RVNT Matrix protein M of the RSV strain ATCC VR-26  long: Amino acid sequence according to SEQ ID No. 4: METYVNKLHE GSTYTAAVQY NVLEKDDDPA SLTIWVPMFQ  SSMPADLLIK ELANVNILVK QISTPKGPSL RVMINSRSAL  LAQMPSKFTI CANVSLDERS KLAYDVTTPC EIKACSLTCL  KSKNMLTTVK DLTMKTLNPT HDIIALCEFE NIVTSKKVII  PTYLRSISVR NKDLNTLENI TTTEFKNAIT NAKIIPYSGL  LLVITVTDNK GAFKYIKPQS QFIVDLGAYL EKESIYYVTT  NWKHTATRFA IKPMED Nucleoprotein N of the RSV strain ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 5: MALSKVKLND TLNKDQLLSS SKYTIQRSTG DSIDTPNYDV  QKHINKLCGM LLITEDANHK FTGLIGMLYA MSRLGREDTI  KILRDAGYHV KANGVDVTTH RQDINGKEMK FEVLTLASLT TEIQINIEIE SRKSYKKMLK EMGEVAPEYR HDSPDCGMII  LCIAALVITK LAAGDRSGLT AVIRRANNVL KNEMKRYKGL  LPKDIANSFY EVFEKHPHFI DVFVHFGIAQ SSTRGGSRVE GIFAGLFMNA YGAGQVMLRW GVLAKSVKNI MLGHASVQAE  MEQVVEVYEY AQKLGGEAGF YHILNNPKAS LLSLTQFPHF  SSVVLGNAAG LGIMGEYRGT PRNQDLYDAA KAYAEQLKEN GVINYSVLDL TAEELEAIKH QLNPKDNDVE L Large polymerase L of the RSV strain ATCC VR-26  long: Amino acid sequence according to SEQ ID No. 6: MDPIINGNSA NVYLTDSYLK GVISFSECNA LGSYIFNGPY  LKNDYTNLIS RQNPLIEHMN LKKLNITQSL ISKYHKGEIK  LEEPTYFQSL LMTYKSMTSL EQIATTNLLK KIIRRAIEIS DVKVYAILNK LGLKEKDKIK SNNGQDEDNS VITTIIKDDI  LSAVKDNQSH LKADKNHSTK QKDTIKTTLL KKLMCSMQHP  PSWLIHWFNL YTKLNNILTQ YRSNEVKNHG FILIDNQTLS GFQFILNQYG CIVYHKELKR ITVTTYNQFL TWKDISLSRL  NVCLITWISN CLNTLNKSLG LRCGFNNVIL TQLFLYGDCI  LKLFHNEGFY IIKEVEGFIM SLILNITEED QFRKRFYNSM LNNITDAANK AQKNLLSRVC HTLLDKTVSD NIINGRWIIL  LSKFLKLIKL AGDNNLNNLS ELYFLFRIFG HPMVDERQAM  DAVKVNCNET KFYLLSSLSM LRGAFIYRII KGFVNNYNRW PTLRNAIVLP LRWLTYYKLN TYPSLLELTE RDLIVLSGLR  FYREFRLPKK VDLEMIINDK AISPPKNLIW TSFPRNYMPS  HIQNYIEHEK LKFSESDKSR RVLEYYLRDN KFNECDLYNC VVNQSYLNNP NHVVSLTGKE RELSVGRMFA MQPGMFRQVQ  ILAEKMIAEN ILQFFPESLT RYGDLELQKI LELKAGISNK  SNRYNDNYNN YISKCSIITD LSKFNQAFRY ETSCICSDVL DELHGVQSLF SWLHLTIPHV TIICTYRHAP PYIRDHIVDL  NNVDEQSGLY RYHMGGIEGW CQKLWTIEAI SLLDLISLKG  KFSITALING DNQSIDISKP VRLMEGQTHA QADYLLALNS LKLLYKEYAG IGHKLKGTET YISRDMQFMS KTIQHNGVYY  PASIKKVLRV GPWINTILDD FKVSLESIGS LTQELEYRGE  SLLCSLIFRN VWLYNQIALQ LKNHALCNNK LYLDILKVLK HLKTFFNLDN IDTALTLYMN LPMLFGGGDP NLLYRSFYRR  TPDFLTEAIV HSVFILSYYT NHDLKDKLQD LSDDRLNKFL  TCIITFDKNP NAEFVTLMRD PQALGSERQA KITSEINRLA VTEVLSTAPN KIFSKSAQHY TTTEIDLNDI MQNIEPTYPH  GLRVVYESLP FYKAEKIVNL ISGTKSITNI LEKTSAIDLT  DIDRATEMMR KNITLLIRIL PLDCNRDKRE ILSMENLSIT ELSKYVRERS WSLSNIVGVT SPSIMYTMDI KYTTSTIASG  IIIEKYNVNS LTRGERGPTK PWVGSSTQEK KTMPVYNRQV  LTKKQRDQID LLAKLDWVYA SIDNKDEFME ELSIGTLGLT YEKAKKLFPQ YLSVNYLHRL TVSSRPCEFP ASIPAYRTTN  YHFDTSPINR ILTEKYGDED IDIVFQNCIS FGLSLMSVVE  QFTNVCPNRI ILIPKLNEIH LMKPPIFTGD VDIHKLKQVI QKQHMFLPDK ISLTQYVELF LSNKTLKSGS HVNSNLILAH  KISDYFHNTY ILSTNLAGHW ILIIQLMKDS KGIFEKDWGE  GYITDHMFIN LKVFFNAYKT YLLCFHKGYG KAKLECDMNT SDLLCVLELI DSSYWKSMSK VFLEQKVIKY ILSQDASLHR  VKGCHSFKLW FLKRLNVAEF TVCPWVVNID YHPTHMKAIL  TYIDLVRMGL INIDRIHIKN KHKFNDEFYT SNLFYINYNF SDNTHLLTKH IRIANSELEN NYNKLYHPTP ETLENILANP  IKSNDKKTLN DYCIGKNVDS IMLPLLSNKK LVKSSAMIRT  NYSKQDLYNL FPTVVIDRII DHSGNTAKSN QLYTTTSHQI SLVHNSTSLY CMLPWHHINR FNFVFSSTGC KISIEYILKD  LKIKDPNCIA FIGEGAGNLL LRTVVELHPD IRYIYRSLKD  CNDHSLPIEF LRLYNGHINI DYGENLTIPA TDATNNIHWS YLHIKFAEPI SLFVCDAELP VTVNWSKIII EWSKHVRKCK  YCSSVNKCTL IVKYHAQDDI DFKLDNITIL KTYVCLGSKL  KGSEVYLVLT IGPANIFPVF NVVQNAKLIL SRTKNFIMPK KADKESIDAN IKSLIPFLCY PITKKGINTA LSKLKSVVSG  DILSYSIAGR NEVESNKLIN HKHMNILKWF NHVLNFRSTE  LNYNHLYMVE STYPYLSELL NSLTTNELKK LIKITGSLLY NFHNE M2-1 protein of the RSV strain ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 7: MSRRNPCKFE IRGHCLNGKR CHF SHNYFEW PPHALLVRQN  FMLNRILKSM DKSIDTLSEI SGAAELDRTE EYALGVVGVL  ESYIGSINNI TKQSACVAMS KLLTELNSDD IKKLRDNEEL NSPKIRVYNT VISYIESNRK NNKQTIHLLK RLPADVLKKT  IKNTLDIHKS ITINNPKELT VSDTNDHAKN NDTT M2-2 protein of the RSV strain ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 8: MTMPKIMILP DKYPCSITSI LITSRCRVTM YNRKNTLYFN  QNNPNNHMYS PNQTFNEIHW TSQDLIDTIQ NFLQHLGVIE  DIYTIYILVS Phosphoprotein P of the RSV strain ATCC VR-26  long: Amino acid sequence according to SEQ ID No. 9: MEKFAPEFHG EDANNRATKF LESIKGKFTS PKDPKKKDSI  ISVNSIDIEV TKESPITSNS TIINPTNETD DNAGNKPNYQ  RKPLVSFKED PIPSDNPFSK LYKETIETFD NNEEESSYSY EEINDQTNDN ITARLDRIDE KLSEILGMLH TLVVASAGPT  SARDGIRDAM VGLREEMIEK IRTEALMTND RLEAMARLRN  EESEKMAKDT SDEVSLNPTS EKLNNLLEGN DSDNDLSLED F Non-structural protein NS1 of the RSV strain ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 10: MGSNSLSMIK VRLQNLFDND EVALLKITCY TDKLIHLTNA  LAKAVIHTIK LNGIVFVHVI TSSDICPNNN IVVKSNFTTM  PVLQNGGYIW EMMELTHCSQ PNGLIDDNCE IKFSKKLSDS TMTNYMNQLS ELLGFDLNP Non-structural protein NS2 of the RSV strain ATCC VR-26 long: Amino acid sequence according to SEQ ID No. 11: MDTTHNDTTP QRLMITDMRP LSLETTITSL TRDIITHRFI  YLINHECIVR KLDERQATFT FLVNYEMKLL HKVGSTKYKK  YTEYNTKYGT FPMPIFINHD GFLECIGIKP TKHTPIIYKY DLNP

In the context of the invention, additionally to the here disclosed amino acid sequences according to SEQ ID Nos. 1-11, also amino acid sequences of different Respiratory syncytial virus (RSV) isolates can be used according to the invention and are incorporated herewith. These Respiratory syncytial virus (RSV) isolates show preferably an identity of at least 70%, more preferably of at least 80% and most preferably of at least 90% with the amino acid sequences according to SEQ ID Nos. 1-11.

Furthermore, in this context the coding region encoding at least one antigenic peptide or protein derived from the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof, may be selected from any nucleic acid sequence comprising a coding region derived from any Respiratory syncytial virus (RSV) isolate or a fragment or variant thereof.

Particularly preferred are the wild type mRNA sequences of the coding regions of the RSV strain long (ATCC VR-26) according to the NCBI accession No. AY911262:

mRNA coding for the fusion protein F of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 12: auggaguugccaauccucaaagcaaaugcaauuaccacaauccucgcugcagucacauuuugcuuugcuucuagucaaaacau cacugaagaauuuuaucaaucaacaugcagugcaguuagcaaaggcuaucuuagugcucuaagaacugguugguauacuagu guuauaacuauagaauuaaguaauaucaaggaaaauaaguguaauggaacagaugcuaagguaaaauugauaaaccaagaauu agauaaauauaaaaaugcuguaacagaauugcaguugcucaugcaaagcacaacagcagcaaacaaucgagccagaagagaacu accaagguuuaugaauuauacacucaacaauaccaaaaaaaccaauguaacauuaagcaagaaaaggaaaagaagauuucuugg uuuuuuguuagguguuggaucugcaaucgccaguggcauugcuguaucuaagguccugcacuuagaaggagaagugaacaa gaucaaaagugcucuacuauccacaaacaaggccguagucagcuuaucaaauggaguuagugucuuaaccagcaaaguguuag accucaaaaacuauauagauaaacaauuguuaccuauugugaauaagcaaagcugcagaauaucaaauauagaaacugugaua gaguuccaacaaaagaacaacagacuacuagagauuaccagggaauuuaguguuaaugcagguguaacuacaccuguaagcac uuacauguuaacuaauagugaauuauugucauuaaucaaugauaugccuauaacaaaugaucagaaaaaguuaauguccaaca auguucaaauaguuagacagcaaaguuacucuaucauguccauaauaaaagaggaagucuuagcauauguaguacaauuacca cuauauggugugauagauacaccuuguuggaaauuacacacauccccucuauguacaaccaacacaaaagaagggucaaacau cuguuuaacaagaacugacagaggaugguacugugacaaugcaggaucaguaucuuucuucccacaagcugaaacauguaaa guucaaucgaaucgaguauuuugugacacaaugaacaguuuaacauuaccaagugaaguaaaucucugcaauguugacauau ucaaucccaaauaugauuguaaaauuaugacuucaaaaacagauguaagcagcuccguuaucacaucucuaggagccauugug ucaugcuauggcaaaacuaaauguacagcauccaauaaaaaucguggaaucauaaagacauuuucuaacgggugugauuaug uaucaaauaaagggguggacacugugucuguagguaacacauuauauuauguaaauaagcaagaaggcaaaagucucuaugu aaaaggugaaccaauaauaaauuucuaugacccauuaguauuccccucugaugaauuugaugcaucaauaucucaagucaaug agaagauuaaccagaguuuagcauuuauucguaaauccgaugaauuauuacaucauguaaaugcugguaaaucaaccacaaau aucaugauaacuacuauaauuauagugauuauaguaauauuguuaucauuaauugcuguuggacugcuccuauacuguaagg ccagaagcacaccagucacacuaagcaaggaucaacugagugguauaaauaauauugcauuuaguaacuga mRNA coding for the glycoprotein G of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 13: auguccaaaaacaaggaccaacgcaccgcuaagacacuagaaaagaccugggacacucucaaucauuuauuauucauaucaucg ggcuuauauaaguuaaaucuuaaaucuauagcacaaaucacauuauccauucuggcaaugauaaucucaacuucacuuauaau uacagccaucauauucauagccucggcaaaccacaaagucacacuaacaacugcaaucauacaagaugcaacaagccagaucaa gaacacaaccccaacauaccucacucaggauccucagcuuggaaucagcuucuccaaucugucugaaauuacaucacaaaccac caccauacuagcuucaacaacaccaggagucaagucaaaccugcaacccacaacagucaagacuaaaaacacaacaacaacccaa acacaacccagcaagcccacuacaaaacaacgccaaaacaaaccaccaaacaaacccaauaaugauuuucacuucgaaguguuua acuuuguacccugcagcauaugcagcaacaauccaaccugcugggcuaucugcaaaagaauaccaaacaaaaaaccaggaaaga aaaccaccaccaagccuacaaaaaaaccaaccuucaagacaaccaaaaaagaucucaaaccucaaaccacuaaaccaaaggaagua cccaccaccaagcccacagaagagccaaccaucaacaccaccaaaacaaacaucacaacuacacugcucaccaacaacaccacagg aaauccaaaacucacaagucaaauggaaaccuuccacucaaccuccuccgaaggcaaucuaagcccuucucaagucuccacaac auccgagcacccaucacaacccucaucuccacccaacacaacacgccaguag mRNA coding for the Short hydrophobic protein SH of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 14: auggaaaauacauccauaacaauagaauucucaagcaaauucuggccuuacuuuacacuaauacacaugaucacaacaauaauc ucuuugcuaaucauaaucuccaucaugacugcaauacuaaacaaacuuugugaauauaacguauuccauaacaaaaccuuuga guuaccaagagcucgagucaacacauag mRNA coding for the matrixprotein M of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 15: auggaaacauacgugaacaagcuucacgaaggcuccacauacacagcugcuguucaauacaauguccuagaaaaagacgauga cccugcaucacuuacaauaugggugcccauguuccaaucaucuaugccagcagauuuacuuauaaaagaacuagcuaauguca acauacuagugaaacaaauauccacacccaagggaccuucacuaagagucaugauaaacucaagaagugcauugcuagcacaaa ugcccagcaaauuuaccauaugugcuaauguguccuuggaugaaagaagcaaacuggcauaugauguaaccacacccugugaa aucaaggcauguagucuaacaugccuaaaaucaaaaaauauguuaacuacaguuaaagaucucacuaugaagacacucaacccc acacaugauauuauugcuuuaugugaauuugaaaacauaguaacaucaaaaaaagucauaauaccaacauaccuaagauccau cagugucagaaauaaagaucugaacacacuugaaaauauaacaaccacugaauucaaaaaugccaucacaaaugcaaaaaucau cccuuacucaggauuacuauuagucaucacagugacugacaacaaaggagcauucaaauacauaaagccgcaaagucaauuca uaguagaucuuggagcuuaccuagaaaaagaaaguauauauuauguuaccacaaauuggaagcacacagcuacacgauuugca aucaaacccauggaagauuaa mRNA coding for the nucleoprotein N of the RSV strain ATCC VR-26 long: mRNA sequence according to SEO ID No. 16: auggcucuuagcaaagucaaguugaaugauacacucaacaaagaucaacuucugucaucuagcaaauacaccauccaacggag cacaggagauaguauugauacuccuaauuaugaugugcagaaacacaucaauaaguuauguggcauguuauuaaucacagaa gaugcuaaucauaaauucacuggguuaauagguauguuauaugcuaugucuagguuaggaagagaagacaccauaaaaauac ucagagaugcgggauaucauguaaaagcaaauggaguagauguaacaacacaucgucaagacaucaaugggaaagaaaugaaa uuugaaguguuaacauuggcaagcuuaacaacugaaauucaaaucaacauugagauagaaucuagaaaauccuacaaaaaaau gcuaaaagaaaugggagagguagcuccagaauacaggcaugauucuccugauugugggaugauaauauuauguauagcagca uuaguaauaaccaaauuggcagcaggggauagaucuggucuuacagccgugauuaggagagcuaauaauguccuaaaaaaug aaaugaaacguuacaaaggcuuacuacccaaggauauagccaacagcuucuaugaaguguuugaaaaacauccccacuuuaua gauguuuuuguucauuuugguauagcacaaucuuccaccagagguggcaguagaguugaagggauuuuugcaggauuguuu augaaugccuauggugcagggcaaguaaugcuacgguggggagucuuagcaaaaucaguuaaaaauauuauguuaggacaug cuagugugcaagcagaaauggaacaaguuguugagguuuaugaauaugcccaaaaauuggguggagaagcaggauucuacca uauauugaacaacccaaaagcaucauuauuaucuuugacucaauuuccucacuuuuccaguguaguauuaggcaaugcugcu ggccuaggcauaaugggagaguacagagguacaccgaggaaucaagaucuauaugaugcagcaaaggcauaugcugaacaacu caaagaaaauggugugauuaacuacaguguauuagacuugacagcagaagaacuagaggcuaucaaacaucagcuuaauccaa aagauaaugauguagagcuuuga mRNA coding for the Large polymerase L of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 17: auggaucccauuauuaauggaaauucugcuaauguuuaucuaaccgauaguuauuuaaaagguguuaucucuuucucagagu guaaugcuuuaggaaguuacauauucaaugguccuuaucucaaaaaugauuauaccaacuuaauuaguagacaaaauccauua auagaacacaugaaucuaaagaaacuaaauauaacacaguccuuaauaucuaaguaucauaaaggugaaauaaaauuagaaga gccuacuuauuuucagucauuacuuaugacauacaagaguaugaccucguuggaacagauugcuaccacuaauuuacuuaaa aagauaauaagaagagcuauagaaauaagugaugucaaagucuaugcuauauugaauaaacuagggcuuaaagaaaaggacaa gauuaaauccaacaauggacaggaugaagacaacucaguuauuacgaccauaaucaaagaugauauacuuucagcuguuaagg auaaucaaucucaucuuaaagcagacaaaaaucacucuacaaaacaaaaagacacaaucaaaacaacacucuugaagaaauuaau guguucaaugcagcauccuccaucaugguuaauacauugguuuaauuuauacacaaaauuaaacaacauauuaacacaguauc gaucaaaugagguuaaaaaccauggguuuauauugauagauaaucaaacucuuaguggauuucaauuuauuuugaaucaaua ugguuguauaguuuaucauaaggaacucaaaagaauuacugugacaaccuauaaucaauucuugacauggaaagauauuagc cuuaguagauuaaauguuuguuuaauuacauggauuaguaacugcuugaacacauuaaauaaaagcuuaggcuuaagaugcg gauucaauaauguuaucuugacacaacuauuccuuuauggugauuguauacuaaagcuauuucacaaugagggguucuacau aauaaaagagguagagggauuuauuaugucucuaauuuuaaauauaacagaagaagaucaauucagaaaacgauuuuauaau aguaugcucaacaacaucacagaugcugcuaauaaagcucagaaaaaucugcuaucaagaguaugucauacauuauuagauaa gacaguauccgauaauauaauaaauggcagauggauaauucuauuaaguaaguuccuuaaauuaauuaagcuugcaggugac aauaaccuuaacaaucugagugaacuauauuuuuuguucagaauauuuggacacccaaugguagaugaaagacaagccaugg augcuguuaaaguuaauugcaaugagaccaaauuuuacuuguuaagcaguuugaguauguuaagaggugccuuuauauaua gaauuauaaaaggguuuguaaauaauuacaacagauggccuacuuuaagaaaugcuauuguuuuacccuuaagaugguuaac uuacuauaaacuaaacacuuauccuucuuuguuggaacuuacagaaagagauuugauuguguuaucaggacuacguuucuau cgugaguuucgguugccuaaaaaaguggaucuugaaaugauuauaaaugauaaagcuauaucacccccuaaaaauuugauau ggacuaguuucccuagaaauuauaugccgucacacauacaaaacuauauagaacaugaaaaauuaaaauuuuccgagagugau aaaucaagaagaguauuagaguauuauuuaagagauaacaaauucaaugaaugugauuuauacaacuguguaguuaaucaaa guuaucucaacaacccuaaucaugugguaucauugacaggcaaagaaagagaacucaguguagguagaauguuugcaaugca accgggaauguucagacagguucaaauauuggcagagaaaaugauagcugaaaacauuuuacaauucuuuccugaaagucuu acaagauauggugaucuagaacuacaaaaaauauuagaauugaaagcaggaauaaguaacaaaucaaaucgcuacaaugauaa uuacaacaauuacauuaguaagugcucuaucaucacagaucucagcaaauucaaucaagcauuucgauaugaaacgucaugua uuuguagugaugugcuggaugaacugcaugguguacaaucucuauuuuccugguuacauuuaacuauuccucaugucacaa uaauaugcacauauaggcaugcaccccccuauauaagagaucauauuguagaucuuaacaauguagaugaacaaaguggauua uauagauaucacaugggugguauugaaggguggugucaaaaacuauggaccauagaagcuauaucacuauuggaucuaauau cucucaaagggaaauucucaauuacugcuuuaauuaauggugacaaucaaucaauagauauaagcaaaccagucagacucaug gaaggucaaacucaugcucaagcagauuauuugcuagcauuaaauagccuuaaauuacuguauaaagaguaugcaggcauag gucacaaauuaaaaggaacugagacuuauauaucacgagauaugcaauuuaugaguaaaacaauucaacauaacgguguauau uacccugcuaguauaaagaaaguccuaagagugggaccguggauaaacacuauacuugaugauuucaaagugagucuagaau cuauagguaguuugacacaagaauuagaauauagaggugaaagucuauuaugcaguuuaauauuuagaaauguaugguuaua uaaucaaauugcucuacaauuaaaaaaucaugcguuauguaacaauaaauuauauuuggacauauuaaagguucugaaacacu uaaaaaccuuuuuuaaucuugauaauauugauacagcauuaacauuguauaugaauuuacccauguuauuuggugguggug aucccaacuuguuauaucgaaguuucuauagaagaacuccugauuuccucacagaggcuauaguucacucuguguucauacu uaguuauuauacaaaccaugacuuaaaagauaaacuucaagauuugucagaugauagauugaauaaguucuuaacaugcauaa ucacguuugacaaaaacccuaaugcugaauucguaacauugaugagagauccucaagcuuuagggucugagagacaagcuaaa auuacuagugaaaucaauagacuggcaguuacagagguuuugaguacagcuccaaacaaaauauucuccaaaagugcacaaca uuauaccacuacagagauagaucuaaaugauauuaugcaaaauauagaaccuacauauccucacgggcuaagaguuguuuaug aaaguuuacccuuuuauaaagcagagaaaauaguaaaucuuauaucagguacaaaaucuauaacuaacauacuggaaaagacu ucugccauagacuuaacagauauugauagagccacugagaugaugaggaaaaacauaacuuugcuuauaaggauacuuccau uggauuguaacagagauaaaagagaaauauugaguauggaaaaccuaaguauuacugaauuaagcaaauauguuagggaaag aucuuggucuuuauccaauauaguugguguuacaucacccaguaucauguauacaauggacaucaaauauacaacaagcacua uagcuaguggcauaauuauagagaaauauaauguuaacaguuuaacacguggugagagaggaccaacuaaaccauggguugg uucaucuacacaagagaaaaaaacaaugccaguuuauaauagacaaguuuuaaccaaaaaacaaagagaucaaauagaucuauu agcaaaauuggauuggguguaugcaucuauagauaacaaggaugaauucauggaagaacucagcauaggaacccuuggguua acauaugaaaaggccaaaaaauuauuuccacaauauuuaagugucaacuauuugcaucgccuuacagucaguaguagaccaug ugaauucccugcaucaauaccagcuuauagaacaacaaauuaucacuuugacacuagcccuauuaaucgcauauuaacagaaa aguauggugaugaagauauugacauaguauuccaaaacuguauaagcuuuggccuLiagcuuaaugucaguaguagaacaauu uacuaauguauguccuaacagaauuauucucauaccuaagcuuaaugagauacauuugaugaaaccucccauauucacaggug auguugauauucacaaguuaaaacaagugauacaaaaacagcauauguuuuuaccagacaaaauaaguuugacucaauaugug gaauuauucuuaaguaacaaaacacucaaaucuggaucucauguuaauucuaauuuaauauuggcacauaaaauaucugacua uuuucauaauacuuacauuuuaaguacuaauuuagcuggacauuggauucuaauuauacaacuuaugaaagauucuaaaggu auuuuugaaaaagauuggggagagggauauauaacugaucauauguuuauuaauuugaaaguuuucuucaaugcuuauaag accuaucucuuguguuuucauaaagguuauggcaaagcaaaacuggagugugauaugaacacuucagaucuucuauguguau uggaauuaauagacaguaguuauuggaagucuaugucuaagguauuuuuagaacaaaaaguuaucaaauacauucuuagcca agaugcaaguuuacauagaguaaaaggaugucauagcuucaaauuaugguuucuuaaacgucuuaauguagcagaauuuaca guuugcccuuggguuguuaacauagauuaucauccaacacauaugaaagcaauauuaacuuauauagaucuuguuagaaugg gauugauaaauauagauagaauacacauuaaaaauaaacacaaauucaaugaugaauuuuauacuucuaaucucuuuuacauu aauuauaacuucucagauaauacucaucuauuaacuaaacauauaaggauugcuaauucagaauuagaaaauaauuacaacaa auuauaucauccuacaccagaaacccuagagaauauacuagccaauccgauuaaaaguaaugacaaaaagacacugaacgacua uuguauagguaaaaauguugacucaauaauguuaccauuguuaucuaauaagaagcuuguuaaaucgucugcaaugauuaga accaauuacagcaaacaagaccuguacaaucuauucccuacgguugugaucgauagaauuauagaucauucagguaauacagc caaauccaaccaacuuuacacuacuacuucccaucaaauaucuuuagugcacaauagcacaucacuuuauugcaugcuuccuu ggcaucauauuaauagauucaauuuuguauuuaguucuacagguuguaaaauuaguauagaguauauuuuaaaagaccuuaa aauuaaagauccuaauuguauagcauucauaggugaaggagcagggaauuuauuauugcguacagugguggaacuucauccu gacauaagauauauuuacagaagucugaaagauugcaaugaucauaguuuaccuauugaguuuuuaaggcuauacaauggac auaucaacauugauuauggugaaaauuugaccauuccugcuacagaugcaaccaacaacauucauuggucuuauuuacauaua aaguuugcugaaccuaucagucuuuuuguaugugaugccgaauugccuguaacagucaacuggaguaaaauuauaauagaau ggagcaagcauguaagaaaaugcaaguacuguuccucaguuaauaaauguacguuaauaguaaaauaucaugcucaagauga uauugauuucaaauuagacaauauaacuauauuaaaaacuuauguaugcuuaggcaguaaguuaaagggaucggagguuuac uuaguccuuacaauagguccugcaaauauauuuccaguauuuaauguaguacaaaaugcuaaauugauacuaucaagaaccaa aaauuucaucaugccuaagaaagcugauaaagagucuauugaugcaaauauuaaaaguuugauacccuuucuuuguuacccu auaacaaaaaaaggaauuaauacugcauugucaaaacuaaagaguguuguuaguggagauauacuaucauauucuauagcug gacggaaugaaguuuucagcaauaaacuuauaaaucauaagcauaugaacaucuuaaagugguucaaucauguuuuaaauuu cagaucaacagaacuaaacuauaaccauuuauauaugguagaaucuacauauccuuaccuaagugaauuguuaaacagcuuga caacuaaugaacuuaaaaaacugauuaaaaucacagguagucuguuauacaacuuucauaaugaauaa mRNA coding for the protein M2-1 of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 18: Augucacgaaggaauccuugcaaauuugaaauucgaggucauugcuugaaugguaagagaugucauuuuagucauaauuau uuugaauggccaccccaugcacugcucguaagacaaaacuuuauguuaaacagaauacuuaagucuauggauaaaaguauaga uaccuuaucagaaauaaguggagcugcagaguuggacagaacagaagaguaugcucuugguguaguuggagugcuagagag uuauauaggaucaauaaauaauauaacuaaacaaucagcauguguugccaugagcaaacuccucacugaacucaauagugaug auaucaaaaaacugagagacaaugaagagcuaaauucacccaagauaagaguguacaauacugucauaucauauauugaaagc aacaggaaaaacaauaaacaaacuauccaucuguuaaaaagauugccagcagacguauugaagaaaaccaucaaaaacacauug gauauccacaagagcauaaccaucaacaacccaaaagaauuaacuguuagugauacaaaugaccaugccaaaaauaaugauacu accuga mRNA coding for the protein M2-2 of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 19: augaccaugccaaaaauaaugauacuaccugacaaauauccuuguaguauaacuuccauacuaauaacaaguagauguagagu cacuauguauaaucgaaagaacacacuauauuucaaucaaaacaacccaaauaaccauauguacucaccgaaucaaacauucaa ugaaauccauuggaccucacaagacuugauugacacaauucaaaauuuucuacagcaucuagguguuauugaggauauauau acaauauauauauuagugucauaa mRNA coding for the phosphoprotein P of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 20: auggaaaaguuugcuccugaauuccauggagaagaugcaaacaacagggcuacuaaauuccuagaaucaauaaagggcaaauu cacaucaccuaaagaucccaagaaaaaagauaguaucauaucugucaacucaauagauauagaaguaaccaaagaaagcccuau aacaucaaauucaaccauuauuaacccaacaaaugagacagaugauaaugcagggaacaagcccaauuaucaaagaaaaccucu aguaaguuucaaagaagacccuauaccaagugauaaucccuuuucaaaacuauacaaagaaaccauagagacauuugauaacaa ugaagaagaaucuagcuauucauaugaagaaauaaaugaucagacgaacgauaauauaacugcaagauuagauaggauugaug aaaaauuaagugaaauacuaggaaugcuucacacauuaguaguagcaagugcaggaccuacaucugcuagggaugguauaag agaugccaugguugguuuaagagaagaaaugauagaaaaaaucagaacugaagcauuaaugaccaaugacagauuagaagcua uggcaagacucaggaaugaggaaagugaaaagauggcaaaagacacaucagaugaagugucucucaauccaacaucagagaaa uugaacaaccuguuggaagggaaugauagugacaaugaucuaucacuugaagauuucuga mRNA coding for the non-structural protein NS1 of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 21: augggcagcaauucguugaguaugauaaaaguuagauuacaaaauuuguuugacaaugaugaaguagcauuguuaaaaauaa caugcuauacugacaaauuaauacauuuaacuaaugcuuuggcuaaggcagugauacauacaaucaaauugaauggcauugu guuugugcauguuauuacaaguagugauauuugcccuaauaauaauauuguaguaaaauccaauuucacaacaaugccagug cuacaaaauggagguuauauaugggaaaugauggaauuaacacauugcucucaaccuaauggucuaauagaugacaauugug aaauuaaauucuccaaaaaacuaagugauucaacaaugaccaauuauaugaaucaauuaucugaauuacuuggauuugaucuu aauccauaa mRNA coding for the non-structural protein NS2 of the RSV strain ATCC VR-26 long: mRNA sequence according to SEQ ID No. 22: auggacacaacccacaaugauaccacaccacaaagacugaugaucacagacaugagaccguugucacuugagacuacaauaaca ucacuaaccagagacaucauaacacacagauuuauauacuuaauaaaucaugaaugcauagugagaaaacuugaugaaagaca ggccacauuuacauuccuggucaacuaugaaaugaaacuauugcacaaaguaggaagcacuaaauauaaaaaauauacugaau acaacacaaaauauggcacuuucccuaugccgauauucaucaaucaugauggguucuuagaaugcauuggcauuaagccuaca aagcauacucccauaauauacaaguaugaucucaauccauag

In the context of the invention, additionally to the here disclosed nucleic acid sequences, also nucleic acid sequences of different Respiratory syncytial virus (RSV) isolates are incorporated herewith. These different Respiratory syncytial virus (RSV) isolates show preferably an identity of at least 50%, 60%, 70%, more preferably of at least 80% and most preferably of at least 90% with the nucleic acid sequences according to SEQ ID Nos. 12-22 or of fragments thereof.

In a preferred embodiment, the mRNA sequence according to the invention does not comprise a reporter gene or a marker gene. Preferably, the mRNA sequence according to the invention does not encode, for instance, luciferase; green fluorescent protein (GFP) and its variants (such as eGFP, RFP or BFP); α-globin; hypoxanthine-guanine phosphoribosyltransferase (HGPRT); β-galactosidase; galactokinase; alkaline phosphatase; secreted embryonic alkaline phosphatase (SEAP)) or a resistance gene (such as a resistance gene against neomycin, puromycin, hygromycin and zeocin). In a preferred embodiment, the mRNA sequence according to the invention does not encode luciferase. In another embodiment, the mRNA sequence according to the invention does not encode GFP or a variant thereof.

In a further preferred embodiment, the mRNA sequence according to the invention does not encode a protein (or a fragment of a protein) derived from a virus belonging to the family of Orthomyxoviridae. Preferably the mRNA sequence does not encode a protein that is derived from an influenza virus, more preferably an influenza A virus. Preferably, the mRNA sequence according to the invention does not encode an influenza A protein selected from the group consisting of hemagglutinin (HA), neuraminidase (NA), nucleoprotein (NP), M1, M2, NS1, NS2 (NEP: nuclear export protein), PA, PB1 (polymerase basic 1), PB1-F2 and PB2. In another preferred embodiment, the mRNA according to the invention does not encode ovalbumin (OVA) or a fragment thereof. Preferably, the mRNA sequence according to the invention does not encode an influenza A protein or ovalbumin.

By a further embodiment, the inventive mRNA preferably comprises at least one of the following structural elements: a 5′- and/or 3′-untranslated region element (UTR element), particularly a 5′-UTR element which comprises or consists of a nucleic acid sequence which is derived from the 5′-UTR of a TOP gene or from a fragment, homolog or a variant thereof, or a 5′- and/or 3′-UTR element which may be derivable from a gene that provides a stable mRNA or from a homolog, fragment or variant thereof; a histone-stem-loop structure, preferably a histone-stem-loop in its 3′ untranslated region; a 5′-CAP structure; a poly-A tail; or a poly(C) sequence.

In a preferred embodiment of the first aspect of the present invention, the inventive mRNA comprises at least one 5′- or 3′-UTR element. In this context, an UTR element comprises or consists of a nucleic acid sequence which is derived from the 5′- or 3′-UTR of any naturally occurring gene or which is derived from a fragment, a homolog or a variant of the 5′- or 3′-UTR of a gene. Preferably, the 5′- or 3′-UTR element used according to the present invention is heterologous to the coding region of the inventive mRNA sequence. Even if 5′- or 3′-UTR elements derived from naturally occurring genes are preferred, also synthetically engineered UTR elements may be used in the context of the present invention.

In a particularly preferred embodiment of the first aspect of the present invention, the inventive mRNA sequence comprises at least one 5′-untranslated region element (5′UTR element) which comprises or consists of a nucleic acid sequence which is derived from the 5′UTR of a TOP gene or which is derived from a fragment, homolog or variant of the 5′UTR of a TOP gene.

It is particularly preferred that the 5′UTR element does not comprise a TOP-motif or a 5′TOP, as defined above.

In some embodiments, the nucleic acid sequence of the 5′UTR element which is derived from a 5′UTR of a TOP gene terminates at its 3′-end with a nucleotide located at position 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 upstream of the start codon (e.g. A(U/T)G) of the gene or mRNA it is derived from. Thus, the 5′UTR element does not comprise any part of the protein coding region. Thus, preferably, the only protein coding part of the inventive mRNA is provided by the coding region.

The nucleic acid sequence, which is derived from the 5′UTR of a TOP gene, is derived from a eukaryotic TOP gene, preferably a plant or animal TOP gene, more preferably a chordate TOP gene, even more preferably a vertebrate TOP gene, most preferably a mammalian TOP gene, such as a human TOP gene.

For example, the 5′UTR element is preferably selected from 5′-UTR elements comprising or consisting of a nucleic acid sequence, which is derived from a nucleic acid sequence selected from the group consisting of SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700, whose disclosure is incorporated herein by reference, from the homologs of SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700, from a variant thereof, or preferably from a corresponding RNA sequence. The term “homologs of SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700” refers to sequences of other species than homo sapiens, which are homologous to the sequences according to SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700.

In a preferred embodiment, the 5′UTR element comprises or consists of a nucleic acid sequence which is derived from a nucleic acid sequence extending from nucleotide position 5 (i.e. the nucleotide that is located at position 5 in the sequence) to the nucleotide position immediately 5′ to the start codon (located at the 3′ end of the sequences), e.g. the nucleotide position immediately 5′ to the ATG sequence, of a nucleic acid sequence selected from SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700, from the homologs of SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700, from a variant thereof, or a corresponding RNA sequence. It is particularly preferred that the 5′ UTR element is derived from a nucleic acid sequence extending from the nucleotide position immediately 3′ to the 5′ TOP to the nucleotide position immediately 5′ to the start codon (located at the 3′ end of the sequences), e.g. the nucleotide position immediately 5′ to the ATG sequence, of a nucleic acid sequence selected from SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700, from the homologs of SEQ ID Nos. 1-1363, SEQ ID NO. 1395, SEQ ID NO. 1421 and SEQ ID NO. 1422 of the patent application WO2013/143700, from a variant thereof, or a corresponding RNA sequence.

In a particularly preferred embodiment, the 5′UTR element comprises or consists of a nucleic acid sequence, which is derived from a 5′UTR of a TOP gene encoding a ribosomal protein or from a variant of a 5′UTR of a TOP gene encoding a ribosomal protein. For example, the 5′UTR element comprises or consists of a nucleic acid sequence which is derived from a 5′UTR of a nucleic acid sequence according to any of SEQ ID NOs: 67, 170, 193, 244, 259, 554, 650, 675, 700, 721, 913, 1016, 1063, 1120, 1138, and 1284-1360 of the patent application WO2013/143700, a corresponding RNA sequence, a homolog thereof, or a variant thereof as described herein, preferably lacking the 5′TOP motif. As described above, the sequence extending from position 5 to the nucleotide immediately 5′ to the ATG (which is located at the 3′end of the sequences) corresponds to the 5′UTR of said sequences.

Preferably, the 5′UTR element comprises or consists of a nucleic acid sequence which is derived from a 5′UTR of a TOP gene encoding a ribosomal Large protein (RPL) or from a homolog or variant of a 5′UTR of a TOP gene encoding a ribosomal Large protein (RPL). For example, the 5′UTR element comprises or consists of a nucleic acid sequence which is derived from a 5′UTR of a nucleic acid sequence according to any of SEQ ID NOs: 67, 259, 1284-1318, 1344, 1346, 1348-1354, 1357, 1358, 1421 and 1422 of the patent application WO2013/143700, a corresponding RNA sequence, a homolog thereof, or a variant thereof as described herein, preferably lacking the 5′ TOP motif.

In a particularly preferred embodiment, the 5′UTR element comprises or consists of a nucleic acid sequence which is derived from the 5′UTR of a ribosomal protein Large 32 gene, preferably from a vertebrate ribosomal protein Large 32 (L32) gene, more preferably from a mammalian ribosomal protein Large 32 (L32) gene, most preferably from a human ribosomal protein Large 32 (L32) gene, or from a variant of the 5′UTR of a ribosomal protein Large 32 gene, preferably from a vertebrate ribosomal protein Large 32 (L32) gene, more preferably from a mammalian ribosomal protein Large 32 (L32) gene, most preferably from a human ribosomal protein Large 32 (L32) gene, wherein preferably the 5′UTR element does not comprise the 5′TOP of said gene.

Accordingly, in a particularly preferred embodiment, the 5′UTR element comprises or consists of a nucleic acid sequence which has an identity of at least about 40%, preferably of at least about 50%, preferably of at least about 60%, preferably of at least about 70%, more preferably of at least about 80%, more preferably of at least about 90%, even more preferably of at least about 95%, even more preferably of at least about 99% to the nucleic acid sequence according to SEQ ID No. 23 (5′-UTR of human ribosomal protein Large 32 lacking the 5′ terminal oligopyrimidine tract: GGCGCTGCCTACGGAGGTGGCAGCCATCTCCTTCTCGGCATC; corresponding to SEQ ID No. 1368 of the patent application WO2013/143700) or preferably to a corresponding RNA sequence, or wherein the at least one 5′UTR element comprises or consists of a fragment of a nucleic acid sequence which has an identity of at least about 40%, preferably of at least about 50%, preferably of at least about 60%, preferably of at least about 70%, more preferably of at least about 80%, more preferably of at least about 90%, even more preferably of at least about 95%, even more preferably of at least about 99% to the nucleic acid sequence according to SEQ ID No. 23 or more preferably to a corresponding RNA sequence, wherein, preferably, the fragment is as described above, i.e. being a continuous stretch of nucleotides representing at least 20%, preferably at least 30%, more preferably at least 40%, more preferably at least 50%, even more preferably at least 60%, even more preferably at least 70%, even more preferably at least 80%, and most preferably at least 90%. of the full-length 5′UTR. Preferably, the fragment exhibits a length of at least about 20 nucleotides or more, preferably of at least about 30 nucleotides or more, more preferably of at least about 40 nucleotides or more. Preferably, the fragment is a functional fragment as described herein.

In some embodiments, the inventive mRNA comprises a 5′UTR element which comprises or consists of a nucleic acid sequence which is derived from the 5′UTR of a vertebrate TOP gene, such as a mammalian, e.g. a human TOP gene, selected from RPSA, RPS2, RPS3, RPS3A, RPS4, RPS5, RPS6, RPS7, RPS8, RPS9, RPS10, RPS11, RPS12, RPS13, RPS14, RPS15, RPS15A, RPS16, RPS17, RPS18, RPS19, RPS20, RPS21, RPS23, RPS24, RPS25, RPS26, RPS27, RPS27A, RPS28, RPS29, RPS30, RPL3, RPL4, RPL5, RPL6, RPL7, RPL7A, RPL8, RPL9, RPL10, RPL10A, RPL11, RPL12, RPL13, RPL13A, RPL14, RPL15, RPL17, RPL18, RPL18A, RPL19, RPL21, RPL22, RPL23, RPL23A, RPL24, RPL26, RPL27, RPL27A, RPL28, RPL29, RPL30, RPL31, RPL32, RPL34, RPL35, RPL35A, RPL36, RPL36A, RPL37, RPL37A, RPL38, RPL39, RPL40, RPL41, RPLP0, RPLP1, RPLP2, RPLP3, RPLP0, RPLP1, RPLP2, EEF1A1, EEF1B2, EEF1D, EEF1G, EEF2, EIF3E, EIF3F, EIF3H, EIF2S3, EIF3C, EIF3K, EIF3EIP, EIF4A2, PABPC1, HNRNPA1, TPT1, TUBB1, UBA52, NPM1, ATP5G2, GNB2L1, NME2, UQCRB, or from a homolog or variant thereof, wherein preferably the 5′UTR element does not comprise a TOP-motif or the 5′TOP of said genes, and wherein optionally the 5′UTR element starts at its 5′-end with a nucleotide located at position 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 downstream of the 5′terminal oligopyrimidine tract (TOP) and wherein further optionally the 5′UTR element which is derived from a 5′UTR of a TOP gene terminates at its 3′-end with a nucleotide located at position 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 upstream of the start codon (A(U/T)G) of the gene it is derived from.

In further particularly preferred embodiments, the 5′UTR element comprises or consists of a nucleic acid sequence which is derived from the 5′UTR of a ribosomal protein Large 32 gene (RPL32), a ribosomal protein Large 35 gene (RPL35), a ribosomal protein Large 21 gene (RPL21), an ATP synthase, H+ transporting, mitochondrial F1 complex, alpha subunit 1, cardiac muscle (ATP5A1) gene, an hydroxysteroid (17-beta) dehydrogenase 4 gene (HSD17B4), an androgen-induced 1 gene (AIG1), cytochrome c oxidase subunit VIc gene (COX6C), or a N-acylsphingosine amidohydrolase (acid ceramidase) 1 gene (ASAH1) or from a variant thereof, preferably from a vertebrate ribosomal protein Large 32 gene (RPL32), a vertebrate ribosomal protein Large 35 gene (RPL35), a vertebrate ribosomal protein Large 21 gene (RPL21), a vertebrate ATP synthase, H+ transporting, mitochondrial F, 1 complex, alpha subunit 1, cardiac muscle (ATP5A1) gene, a vertebrate hydroxysteroid (17-beta) dehydrogenase 4 gene (HSD17B4), a vertebrate androgen-induced 1 gene (AIG1), a vertebrate cytochrome c oxidase subunit VIc gene (COX6C), or a vertebrate N-acylsphingosine amidohydrolase (acid ceramidase) 1 gene (ASAH1) or from a variant thereof, more preferably from a mammalian ribosomal protein Large 32 gene (RPL32), a ribosomal protein Large 35 gene (RPL35), a ribosomal protein Large 21 gene (RPL21), a mammalian ATP synthase, H+ transporting, mitochondrial F1 complex, alpha subunit 1, cardiac muscle (ATP5A1) gene, a mammalian hydroxysteroid (17-beta) dehydrogenase 4 gene (HSD17B4), a mammalian androgen-induced 1 gene (AIG1), a mammalian cyto-chrome c oxidase subunit VIc gene (COX6C), or a mammalian N-acylsphingosine amidohydrolase (acid ceramidase) 1 gene (ASAH1) or from a variant thereof, most preferably from a human ribosomal protein Large 32 gene (RPL32), a human ribosomal protein Large 35 gene (RPL35), a human ribosomal protein Large 21 gene (RPL21), a human ATP synthase, H+ transporting, mitochondrial F, 1 complex, alpha subunit 1, cardiac muscle (ATP5A1) gene, a human hydroxysteroid (17-beta) dehydrogenase 4 gene (HSD17B4), a human androgen-induced 1 gene (AIG1), a human cytochrome c oxidase subunit VIc gene (COX6C), or a human N-acylsphingosine amidohydrolase (acid ceramidase) 1 gene (ASAH1) or from a variant thereof, wherein preferably the 5′UTR element does not comprise the 5′TOP of said gene.

Accordingly, in a particularly preferred embodiment, the 5′UTR element comprises or consists of a nucleic acid sequence which has an identity of at least about 40%, preferably of at least about 50%, preferably of at least about 60%, preferably of at least about 70%, more preferably of at least about 80%, more preferably of at least about 90%, even more preferably of at least about 95%, even more preferably of at least about 99% to the nucleic acid sequence according to SEQ ID No. 1368, or SEQ ID NOs 1412-1420 of the patent application WO2013/143700, or a corresponding RNA sequence, or wherein the at least one 5′UTR element comprises or consists of a fragment of a nucleic acid sequence which has an identity of at least about 40%, preferably of at least about 50%, preferably of at least about 60%, preferably of at least about 70%, more preferably of at least about 80%, more preferably of at least about 90%, even more preferably of at least about 95%, even more preferably of at least about 99% to the nucleic acid sequence according to SEQ ID No. 1368, or SEQ ID NOs 1412-1420 of the patent application WO2013/143700, wherein, preferably, the fragment is as described above, i.e. being a continuous stretch of nucleotides representing at least 20% etc. of the full-length 5′UTR. Preferably, the fragment exhibits a length of at least about 20 nucleotides or more, preferably of at least about 30 nucleotides or more, more preferably of at least about 40 nucleotides or more. Preferably, the fragment is a functional fragment as described herein.

Accordingly, in a particularly preferred embodiment, the 5′UTR element comprises or consists of a nucleic acid sequence which has an identity of at least about 40%, preferably of at least about 50%, preferably of at least about 60%, preferably of at least about 70%, more preferably of at least about 80%, more preferably of at least about 90%, even more preferably of at least about 95%, even more preferably of at least about 99% to the nucleic acid sequence according to SEQ ID No. 36 (5′-UTR of ATP5A1 lacking the 5′ terminal oligopyrimidine tract: GCGGCTCGGCCATTTTGTCCCAGTCAGTCCGGAGGCTGCGGCTGCAGAAGTACCGCCTGCG-GAGTAACTGCAAAG; corresponding to SEQ ID No. 1414 of the patent application WO2013/143700) or preferably to a corresponding RNA sequence, or wherein the at least one 5′UTR element comprises or consists of a fragment of a nucleic acid sequence which has an identity of at least about 40%, preferably of at least about 50%, preferably of at least about 60%, preferably of at least about 70%, more preferably of at least about 80%, more preferably of at least about 90%, even more preferably of at least about 95%, even more preferably of at least about 99% to the nucleic acid sequence according to SEQ ID No. 26 or more preferably to a corresponding RNA sequence, wherein, preferably, the fragment is as described above, i.e. being a continuous stretch of nucleotides representing at least 20% etc. of the full-length 5′UTR. Preferably, the fragment exhibits a length of at least about 20 nucleotides or more, preferably of at least about 30 nucleotides or more, more preferably of at least about 40 nucleotides or more. Preferably, the fragment is a functional fragment as described herein.

In a further preferred embodiment, the inventive mRNA further comprises at least one 3′UTR element, which comprises or consists of a nucleic acid sequence derived from the 3′UTR of a chordate gene, preferably a vertebrate gene, more preferably a mammalian gene, most preferably a human gene, or from a variant of the 3′UTR of a chordate gene, preferably a vertebrate gene, more preferably a mammalian gene, most preferably a human gene.

The term ‘3′UTR element’ refers to a nucleic acid sequence which comprises or consists of a nucleic acid sequence that is derived from a 3′UTR or from a variant of a 3′UTR. A 3′UTR element in the sense of the present invention may represent the 3′UTR of an mRNA. Thus, in the sense of the present invention, preferably, a 3′UTR element may be the 3′UTR of an mRNA, preferably of an artificial mRNA, or it may be the transcription template for a 3′UTR of an mRNA. Thus, a 3′UTR element preferably is a nucleic acid sequence which corresponds to the 3′UTR of an mRNA, preferably to the 3′UTR of an artificial mRNA, such as an mRNA obtained by transcription of a genetically engineered vector construct. Preferably, the 3′UTR element fulfils the function of a 3′UTR or encodes a sequence which fulfils the function of a 3′UTR.

Preferably, the inventive mRNA comprises a 3′UTR element which may be derivable from a gene that relates to an mRNA with an enhanced half-life (that provides a stable mRNA), for example a 3′UTR element as defined and described below.

In a particularly preferred embodiment, the 3′UTR element comprises or consists of a nucleic acid sequence which is derived from a 3′UTR of a gene selected from the group consisting of an albumin gene, an α-globin gene, a β-globin gene, a tyrosine hydroxylase gene, a lipoxygenase gene, and a collagen alpha gene, such as a collagen alpha 1(I) gene, or from a variant of a 3′UTR of a gene selected from the group consisting of an albumin gene, an α-globin gene, a β-globin gene, a tyrosine hydroxylase gene, a lipoxygenase gene, and a collagen alpha gene, such as a collagen alpha 1(I) gene according to SEQ ID No. 1369-1390 of the patent application WO2013/143700 whose disclosure is incorporated herein by reference. In a particularly preferred embodiment, the 3′UTR element comprises or consists of a nucleic acid sequence which is derived from a 3′UTR of an albumin gene, preferably a vertebrate albumin gene, more preferably a mammalian albumin gene, most preferably a human albumin gene according to SEQ ID No. 24.

Human albumin 3′UTR SEQ ID No. 24: CATCACATTT AAAAGCATCT CAGCCTACCA TGAGAATAAG  AGAAAGAAAA TGAAGATCAA AAGCTTATTC ATCTGTTTTT  CTTTTTCGTT GGTGTAAAGC CAACACCCTG TCTAAAAAAC  ATAAATTTCT TTAATCATTT TGCCTCTTTT CTCTGTGCTT  CAATTAATAA AAAATGGAAA GAATCT (corresponding to SEQ ID No1369 of the patent application WO2013/143700).

In this context, it is particularly preferred that the inventive mRNA comprises a 3′-UTR element comprising a corresponding RNA sequence derived from the nucleic acids according to SEQ ID No. 1369-1390 of the patent application WO2013/143700 or a fragment, homolog or variant thereof.

Most preferably the 3′-UTR element comprises the nucleic acid sequence derived from a fragment of the human albumin gene according to SEQ ID No. 25:

albumin7 3′UTR

CATCACATTTAAAAGCATCTCAGCCTACCATGAGAATAAGAGAAAGAAAA TGAAGATCAATAGCTTATTCATCTCTTTTTCTTTTTCGTTGGTGTAAAGC CAACACCCTGTCTAAAAAACATAAATTTCTTTAATCATTTTGCCTCTTTT CTCTGTGCTTCAATTAATAAAAAATGGAAAGAACCT (SEQ ID No.  25 corresponding to SEQ ID No: 1376 of the patent application WO2013/143700)

In this context, it is particularly preferred that the 3′-UTR element of the inventive mRNA comprises or consists of a corresponding RNA sequence of the nucleic acid sequence according to SEQ ID No. 25.

In another particularly preferred embodiment, the 3′UTR element comprises or consists of a nucleic acid sequence which is derived from a 3′UTR of an α-globin gene, preferably a vertebrate α- or β-globin gene, more preferably a mammalian α- or β-globin gene, most preferably a human α- or β-globin gene according to SEQ ID No. 26-28:

3′-UTR of Homo sapiens hemoglobin, alpha 1 (HBA1) GCTGGAGCCTCGGTGGCCATGCTTCTTGCCCCTTGGGCCTCCCCCCAGCC CCTCCTCCCCTTCCTGCACCCGTACCCCCGTGGTCTTTGAATAAAGTCTG AGTGGGCGGC (SEQ ID No: 26 corresponding to SEQ ID No. 1370 of the patent application WO2013/143700) 3′-UTR of Homo sapiens hemoglobin, alpha 2 (HBA2) GCTGGAGCCTCGGTAGCCGTTCCTCCTGCCCGCTGGGCCTCCCAACGGGC CCTCCTCCCCTCCTTGCACCGGCCCTTCCTGGTCTTTGAATAAAGTCTGA GTGGGCAG (SEQ ID No: 27 corresponding to SEQ ID  No. 1371 of the patent application WO2013/143700) 3′-UTR of Homo sapiens hemoglobin, beta (HBB) GCTCGCTTTCTTGCTGTCCAATTTCTATTAAAGGTTCCTTTGTTCCCTAA GTCCAACTACTAAACTGGGGGATATTATGAAGGGCCTTGAGCATCTGGAT TCTGCCTAATAAAAAACATTTATTTTCATTGC (SEQ ID No: 28  corresponding to SEQ ID No. 1372 of the patent application WO2013/143700)

For example, the 3′UTR element may comprise or consist of the center, α-complex-binding portion of the 3′UTR of an α-globin gene, such as of a human α-globin gene, preferably according to SEQ ID No. 29:

Center, α-complex-binding portion of the 3′UTR of an α-globin gene (also named herein as “muag”)

GCCCGATGGGCCTCCCAACGGGCCCTCCTCCCCTCCTTGCACCG  (SEQ ID NO.29 corresponding to SEQ ID No. 1393 of  the patent application WO2013/143700).

In this context, it is particularly preferred that the 3′-UTR element of the inventive mRNA comprises or consists of a corresponding RNA sequence of the nucleic acid sequence according to SEQ ID No. 29 or a homolog, a fragment or variant thereof.

The term ‘a nucleic acid sequence which is derived from the 3′UTR of a [ . . . ] gene’ preferably refers to a nucleic acid sequence which is based on the 3′UTR sequence of a [ . . . ] gene or on a part thereof, such as on the 3′UTR of an albumin gene, an α-globin gene, a β-globin gene, a tyrosine hydroxylase gene, a lipoxygenase gene, or a collagen alpha gene, such as a collagen alpha 1(I) gene, preferably of an albumin gene or on a part thereof. This term includes sequences corresponding to the entire 3′UTR sequence, i.e. the full length 3′UTR sequence of a gene, and sequences corresponding to a fragment of the 3′UTR sequence of a gene, such as an albumin gene, α-globin gene, β-globin gene, tyrosine hydroxylase gene, lipoxygenase gene, or collagen alpha gene, such as a collagen alpha 1(I) gene, preferably of an albumin gene.

The term ‘a nucleic acid sequence which is derived from a variant of the 3′UTR of a [ . . . ] gene’ preferably refers to a nucleic acid sequence which is based on a variant of the 3′UTR sequence of a gene, such as on a variant of the 3′UTR of an albumin gene, an α-globin gene, a β-globin gene, a tyrosine hydroxylase gene, a lipoxygenase gene, or a collagen alpha gene, such as a collagen alpha 1(I) gene, or on a part thereof as described above. This term includes sequences corresponding to the entire sequence of the variant of the 3′UTR of a gene, i.e. the full length variant 3′UTR sequence of a gene, and sequences corresponding to a fragment of the variant 3′UTR sequence of a gene. A fragment in this context preferably consists of a continuous stretch of nucleotides corresponding to a continuous stretch of nucleotides in the full-length variant 3′UTR, which represents at least 20%, preferably at least 30%, more preferably at least 40%, more preferably at least 50%, even more preferably at least 60%, even more preferably at least 70%, even more preferably at least 80%, and most preferably at least 90% of the full-length variant 3′UTR. Such a fragment of a variant, in the sense of the present invention, is preferably a functional fragment of a variant as described herein.

Preferably, the at least one 5′UTR element and the at least one 3′UTR element act synergistically to increase protein production from the inventive mRNA as described above.

In a particularly preferred embodiment, the inventive mRNA comprising a coding region, encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof, comprises a histone stem-loop sequence/structure. Such histone stem-loop sequences are preferably selected from histone stem-loop sequences as disclosed in WO 2012/019780, whose disclosure is incorporated herewith by reference.

A histone stem-loop sequence, suitable to be used within the present invention, is preferably selected from at least one of the following formulae (I) or (II):

formula (I) (stem-loop sequence without stem bordering elements):

formula (II) (stem-loop sequence with stem bordering elements):

wherein:

-   stem1 or stem2 bordering elements N1-6 is a consecutive sequence of     1 to 6, preferably of 2 to 6, more preferably of 2 to 5, even more     preferably of 3 to 5, most preferably of 4 to 5 or 5 N, wherein each     N is independently from another selected from a nucleotide selected     from A, U, T, G and C, or a nucleotide analogue thereof; -   stem1 [N₀₋₂GN₃₋₅] is reverse complementary or partially reverse     complementary with element stem2, and is a consecutive sequence     between of 5 to 7 nucleotides;     -   wherein N₀₋₂ is a consecutive sequence of 0 to 2, preferably of         0 to 1, more preferably of 1 N, wherein each N is independently         from another selected from a nucleotide selected from A, U, T, G         and C or a nucleotide analogue thereof;     -   wherein N3-5 is a consecutive sequence of 3 to 5, preferably of         4 to 5, more preferably of 4 N, wherein each N is independently         from another selected from a nucleotide selected from A, U, T, G         and C or a nucleotide analogue thereof, and     -   wherein G is guanosine or an analogue thereof, and may be         optionally replaced by a cytidine or an analogue thereof,         provided that its complementary nucleotide cytidine in stem2 is         replaced by guanosine; -   loop sequence [N₀₋₄(U/T)N₀₋₄] is located between elements stem1 and     stem2, and is a consecutive sequence of 3 to 5 nucleotides, more     preferably of 4 nucleotides;     -   wherein each N₀₋₄ is independent from another a consecutive         sequence of 0 to 4, preferably of 1 to 3, more preferably of 1         to 2 N, wherein each N is independently from another selected         from a nucleotide selected from A, U, T, G and C or a nucleotide         analogue thereof; and     -   wherein U/T represents uridine, or optionally thymidine; -   stem2 [N₃₋₅CN₀₋₂] is reverse complementary or partially reverse     complementary with element stem1, and is a consecutive sequence     between of 5 to 7 nucleotides;     -   wherein N₃₋₅ is a consecutive sequence of 3 to 5, preferably of         4 to 5, more preferably of 4 N, wherein each N is independently         from another selected from a nucleotide selected from A, U, T, G         and C or a nucleotide analogue thereof;     -   wherein N₀₋₂ is a consecutive sequence of 0 to 2, preferably of         0 to 1, more preferably of 1 N, wherein each N is independently         from another selected from a nucleotide selected from A, U, T, G         or C or a nucleotide analogue thereof; and     -   wherein C is cytidine or an analogue thereof, and may be         optionally replaced by a guanosine or an analogue thereof         provided that its complementary nucleoside guanosine in stem1 is         replaced by cytidine;

wherein

stem1 and stem2 are capable of base pairing with each other forming a reverse complementary sequence, wherein base pairing may occur between stem1 and stem2, e.g. by Watson-Crick base pairing of nucleotides A and U/T or G and C or by non-Watson-Crick base pairing e.g. wobble base pairing, reverse Watson-Crick base pairing, Hoogsteen base pairing, reverse Hoogsteen base pairing or are capable of base pairing with each other forming a partially reverse complementary sequence, wherein an incomplete base pairing may occur between stem1 and stem2, on the basis that one ore more bases in one stem do not have a complementary base in the reverse complementary sequence of the other stem.

According to a further preferred embodiment of the first inventive aspect, the inventive mRNA sequence may comprise at least one histone stem-loop sequence according to at least one of the following specific formulae (Ia) or (IIa):

formula (Ia) (stem-loop sequence without stem bordering elements):

formula (IIa) (stem-loop sequence with stem bordering elements):

wherein:

N, C, G, T and U are as defined above.

According to a further more particularly preferred embodiment of the first aspect, the inventive mRNA sequence may comprise at least one histone stem-loop sequence according to at least one of the following specific formulae (Ib) or (IIb):

formula (Ib) (stem-loop sequence without stem bordering elements):

formula (IIb) (stem-loop sequence with stem bordering elements):

wherein:

N, C, G, T and U are as defined above.

A particular preferred histone stem-loop sequence is the sequence according to SEQ ID NO: 30 CAAAGGCTCTTTTCAGAGCCACCA or more preferably the corresponding RNA sequence of the nucleic acid sequence according to SEQ ID NO: 30 (CAAAGGCUCUUUUCAGAGCCACCA SEQ ID NO: 37).

In a particular preferred embodiment of the first aspect of the present invention the inventive mRNA comprises additionally to the coding region encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof, a poly(A) sequence, also called poly-A-tail, preferably at the 3′-terminus of the inventive mRNA. When present, such a poly(A) sequence comprises a sequence of about 25 to about 400 adenosine nucleotides, preferably a sequence of about 50 to about 400 adenosine nucleotides, more preferably a sequence of about 50 to about 300 adenosine nucleotides, even more preferably a sequence of about 50 to about 250 adenosine nucleotides, most preferably a sequence of about 60 to about 250 adenosine nucleotides. In this context, the term “about” refers to a deviation of ±10% of the value(s) it is attached to. This poly(A) sequence is preferably located 3′ of the coding region comprised in the inventive mRNA according to the first aspect of the present invention.

According to a further preferred embodiment, the inventive mRNA can be modified by a sequence of at least 10 cytosines, preferably at least 20 cytosines, more preferably at least 30 cytosines (so-called “poly(C) sequence”). Particularly, the mRNA may contain a poly(C) sequence of typically about 10 to 200 cytosine nucleotides, preferably about 10 to 100 cytosine nucleotides, more preferably about 10 to 70 cytosine nucleotides or even more preferably about 20 to 50 or even 20 to 30 cytosine nucleotides. This poly(C) sequence is preferably located 3′ of the coding region, more preferably 3′ of an optional poly(A) sequence comprised in the inventive mRNA according to the first aspect of the present invention.

In this context, the inventive mRNA sequence may comprise in a specific embodiment:

-   a.) a 5′-CAP structure, preferably m7GpppN; -   b.) a coding region encoding at least one antigenic peptide or     protein of Respiratory syncytial virus (RSV), preferably derived     from the fusion protein F of Respiratory syncytial virus (RSV); -   c.) a poly(A) sequence preferably comprising 64 adenosines; and -   d.) optionally, a poly(C) sequence, preferably comprising 30     cytosines.

In a particularly preferred embodiment of the first aspect of the present invention the inventive mRNA comprising a coding region encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof, comprises preferably in 5′- to 3′-direction:

-   a.) a 5′-CAP structure, preferably m7GpppN; -   b.) a coding region encoding at least one antigenic peptide or     protein of Rabies virus, preferably derived from the glycoprotein G     (RAV-G) of Rabies virus; -   c.) a poly(A) sequence preferably comprising 64 adenosines; -   d.) optionally, a poly(C) sequence, preferably comprising 30     cytosines; and -   e.) a histone-stem-loop, preferably comprising the corresponding RNA     sequence of the nucleic acid sequence according to SEQ ID NO: 30.

In a further particularly preferred embodiment of the first aspect of the present invention, the inventive mRNA comprising a coding region encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof, comprises preferably in 5′- to 3′-direction:

-   a.) a 5′-CAP structure, preferably m7GpppN; -   b.) a coding region encoding at least one antigenic peptide or     protein of Respiratory syncytial virus (RSV), preferably derived     from the fusion protein F of Respiratory syncytial virus (RSV); -   c.) optionally, a 3′-UTR element derived from an alpha globin gene,     preferably comprising the corresponding RNA sequence of the nucleic     acid sequence according to SEQ ID NO. 29, a homolog, a fragment, or     a variant thereof; -   d.) a poly(A) sequence preferably comprising 64 adenosines; -   e.) optionally, a poly(C) sequence, preferably comprising 30     cytosines; and -   f.) a histone-stem-loop, preferably comprising the corresponding RNA     sequence of the nucleic acid sequence according to SEQ ID NO: 30.

In another particular preferred embodiment, the inventive mRNA encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof, comprises preferably in 5′- to 3′-direction:

-   a.) a 5′-CAP structure, preferably m7GpppN; -   b.) optionally, a 5′-UTR element derived from a TOP gene, preferably     derived from the corresponding RNA sequence of the nucleic acid     sequence according to SEQ ID NO. 23, a homolog, a fragment, or a     variant thereof; -   c.) a coding region encoding at least one antigenic peptide or     protein of Respiratory syncytial virus (RSV), preferably derived     from the fusion protein F of Respiratory syncytial virus (RSV); -   d.) optionally, a 3′UTR element derived of a gene providing a stable     mRNA, preferably derived from the corresponding RNA sequence of a     nucleic acid sequence according to SEQ ID NO. 25, a homolog, a     fragment, or a variant thereof; -   e.) a poly(A) sequence preferably comprising 64 adenosines; -   f.) optionally, a poly(C) sequence, preferably comprising 30     cytosines; and -   g.) a histone-stem-loop, preferably comprising the corresponding RNA     sequence of the nucleic acid sequence according to SEQ ID NO: 30.

The coding region might encode at least partially one of the amino acid sequences according to SEQ ID Nos. 1-11 or fragments, variants or derivatives thereof. Furthermore, the coding region of the inventive mRNA may encode a combination of at least two of these amino acid sequences or a combination of fragments, variants or derivatives thereof. Particularly preferred in this context is a combination of fusion protein F with nucleoprotein N and a combination of fusion protein F and M2-1 protein.

Additionally the coding region might be or might comprise at least partially one of the sequences according to SEQ ID No. 12 to SEQ ID No. 22, or fragments, homologs or variants thereof. Furthermore, the mRNA might comprise a combination of at least two of these sequences or a combination of fragments, homologs or variants thereof.

For further improvement of the resistance to e.g. in vivo degradation (e.g. by an exo- or endo-nuclease), the inventive mRNA may be provided as a stabilized nucleic acid, e.g. in the form of a modified nucleic acid. According to a further embodiment of the invention it is therefore preferred that the inventive mRNA is stabilized, preferably by backbone modifications, sugar modifications and/or base modifications, more preferred stabilized by modification of the G/C-content. All of these modifications may be introduced into the inventive mRNA without impairing the mRNA's function to be translated into the antigenic function derived from the Respiratory syncytial virus (RSV) peptide or protein.

A backbone modification in the context of the present invention is preferably a modification in which phosphates of the backbone of the nucleotides contained in the inventive mRNA are chemically modified, e.g. anionic internucleoside linkage, N3′→P5′ modifications, replacement of non-bridging oxygen atoms by boranes, neutral internucleoside linkage, amide linkage of the nucleosides, methylene(methylimino) linkages, formacetal and thioformacetal linkages, introduction of sulfonyl groups, or the like.

A sugar modification in the context of the present invention is preferably a chemical modification of the sugar of the nucleotides of the inventive mRNA, e.g. methylation of the ribose residue or the like.

According to another embodiment, the inventive mRNA may be modified and thus stabilized by modifying the G (guanosine)/C (cytosine) content of the mRNA, preferably of the coding region thereof.

Therein, the G/C content of the inventive mRNA, preferably of the coding region, is particularly increased compared to the G/C content of the coding region of its particular wild type coding sequence, i.e. the unmodified mRNA. However, the encoded amino acid sequence of the inventive mRNA is preferably not modified compared to the coded amino acid sequence of the particular wild type/unmodified mRNA.

The modification of the G/C-content of the inventive mRNA is based on the fact that RNA sequences having an increased G (guanosine)/C (cytosine) content are more stable than RNA sequences having an increased A (adenosine)/U (uracil) content. The codons of a coding sequence or a whole RNA might therefore be varied compared to the wild type coding sequence or mRNA, such that they include an increased amount of G/C nucleotides while the translated amino acid sequence is retained. In respect to the fact that several codons code for one and the same amino acid (so-called degeneration of the genetic code), the most favourable codons for the stability can be determined (so-called alternative codon usage). Preferably, the G/C content of the coding region of the inventive mRNA according to the invention is increased by at least 7%, more preferably by at least 15%, particularly preferably by at least 20%, compared to the G/C content of the coded region of the wild type RNA. According to a specific embodiment at least 5%, 10%, 20%, 30%, 40%, 50%, 60%, more preferably at least 70%, even more preferably at least 80% and most preferably at least 90%, 95% or even 100% of the substitutable codons in the region coding for a protein or peptide as defined herein or its fragment or variant thereof or the whole sequence of the wild type mRNA sequence or coding sequence are substituted, thereby increasing the G/C content of said sequence. In this context, it is particularly preferable to increase the G/C content of the inventive mRNA to the maximum (i.e. 100% of the substitutable codons), in particular in the coding region, compared to the wild type sequence.

According to a further preferred embodiment of the invention, the inventive mRNA is optimized for translation, preferably optimized for translation by replacing codons for less frequent tRNAs of a given amino acid by codons for more frequently occurring tRNAs of the respective amino acid. This is based on the finding that the translation efficiency is also determined by a different frequency in the occurrence of tRNAs in cells. Thus, if so-called “less frequent codons” are present in the inventive mRNA to an increased extent, the corresponding modified RNA is translated to a significantly poorer degree than in the case where codons coding for more frequent tRNAs are present. Preferably, the coding region of the inventive mRNA is modified compared to the corresponding region of the wild type RNA or coding sequence such that at least one codon of the wild type sequence which codes for a tRNA which is relatively rare or less frequent in the cell is exchanged for a codon which codes for a tRNA which is more or most frequent in the cell and carries the same amino acid as the relatively rare or less frequent tRNA. By this modification, the sequences of the inventive mRNA can be modified such that codons for which more frequently occurring tRNAs are available are inserted. In other words, according to the invention, by this modification all codons of the wild type sequence which code for a tRNA which is relatively rare in the cell can in each case be exchanged for a codon which codes for a respective tRNA which is relatively frequent in the cell and which, in each case, carries the same amino acid as the relatively rare tRNA. Furthermore, it is particularly preferable to link the sequential G/C content which is increased, in particular maximized, in the inventive mRNA with the “frequent” codons without modifying the amino acid sequence of the protein encoded by the coding region of the inventive mRNA or of the coding region. This preferred embodiment allows provision of a particularly efficiently translated and stabilized (modified) inventive mRNA.

Substitutions, additions or eliminations of bases are preferably carried out using a DNA matrix for preparation of the nucleic acid molecule by techniques of the well known site directed mutagenesis or with an oligonucleotide ligation. In such a process, for preparation of the at least one RNA of the inventive combination vaccine as defined herein a corresponding DNA molecule may be transcribed in vitro. This DNA matrix preferably comprises a suitable promoter, e.g. a T7 or SP6 promoter, for in vitro transcription, which is followed by the desired nucleotide sequence for the at least one RNA to be prepared and a termination signal for in vitro transcription. The DNA molecule, which forms the matrix of the at least one RNA of interest, may be prepared by fermentative proliferation and subsequent isolation as part of a plasmid which can be replicated in bacteria. Plasmids which may be mentioned as suitable for the present invention are e.g. the plasmids pT7 Ts (GenBank accession number U26404; Lai et al., Development 1995, 121: 2349 to 2360), pGEM® series, e.g. pGEM®-1 (GenBank accession number X65300; from Promega) and pSP64 (GenBank accession number X65327); cf. also Mezei and Storts, Purification of PCR Products, in: Griffin and Griffin (ed.), PCR Technology: Current Innovation, CRC Press, Boca Raton, Fla., 2001.

In a particularly preferred embodiment, the inventive mRNA sequence according to the first aspect of the present invention comprises, preferably in 5′- to 3′-direction:

-   a) a 5′-CAP structure, as defined herein, preferably m7GpppN; -   b) a coding region, preferably with an increased or even maximized     G/C content compared with the G/C content of the coding region of     the wild type mRNA, encoding at least one antigenic peptide or     protein derived from the fusion protein F, the glycoprotein G, the     short hydrophobic protein SH, the matrix protein M, the     nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2     protein, the phosphoprotein P, the non-structural protein NS1 or the     non-structural protein NS2 of Respiratory syncytial virus (RSV), or     a fragment, variant or derivative thereof; -   c) a 3′-UTR element as defined herein, preferably derived of a gene     providing a stable mRNA, most preferably the corresponding RNA     sequence of the nucleic acid sequence according to SEQ ID No. 29, or     a homolog, a fragment or variant thereof; -   d) a poly(A) sequence, preferably consisting of 64 adenosines -   e) optionally a poly(C) sequence, preferably consisting of 30     cytosines. -   f) at least one histone stem-loop sequence, preferably the     corresponding RNA sequence of the nucleic acid sequence according to     SEQ ID NO. 30.

Most preferably, the inventive mRNA sequence of that specific embodiment comprises the sequence modifications as shown in FIG. 1 (SEQ ID NO. 31) using the example of an inventive mRNA coding for the fusion protein F of RSV long.

In a further particularly preferred embodiment, the inventive mRNA sequence according to the first aspect of the present invention comprises preferably in 5′ to 3′ direction:

-   a) a 5′-CAP structure, as defined herein, preferably m7GpppN; -   b) a 5′-UTR element as defined herein, preferably a 5′-UTR element     which comprises or consists of a nucleic acid sequence which is     derived from the 5′-UTR of a TOP gene, preferably the 5′-UTR of     human ribosomal protein Large 32 lacking the 5′ terminal     oligopyrimidine tract according to SEQ ID No. 23 or the     corresponding RNA sequence; or a fragment, homolog or variant     thereof; -   c) a coding region, preferably with an increased or even maximized     G/C content compared with the G/C content of the coding region of     the wild type mRNA, encoding at least one antigenic peptide or     protein derived from the fusion protein F, the glycoprotein G, the     short hydrophobic protein SH, the matrix protein M, the     nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2     protein, the phosphoprotein P, the non-structural protein NS1 or the     non-structural protein NS2 of Respiratory syncytial virus (RSV) or a     fragment, variant or derivative thereof; -   d) a 3′-UTR element, preferably the 3′-UTR element of human albumin     according to SEQ ID No. 24 or the corresponding RNA, or a homolog, a     fragment or a variant thereof; -   e) a poly(A) sequence, preferably consisting of 64 adenosines -   f) optionally a poly(C) sequence, preferably consisting of 30     cytosines. -   g) at least one histone stem-loop sequence, preferably the     corresponding RNA sequence of the nucleic acid sequence according to     SEQ ID NO. 30.

Most preferably, the inventive mRNA of that specific embodiment comprises the sequence modifications as shown in FIG. 2 (SEQ ID NO. 32) using the example of an inventive mRNA coding for the fusion protein F of RSV long.

In an even more particularly preferred embodiment the inventive mRNA sequence comprises or consists of the sequences shown in FIG. 1-5 according to SEQ ID Nos. 31 and 35.

In further specific embodiments, the mRNA according to the invention may further comprise an internal ribosome entry site (IRES) sequence or IRES-motif, which may separate several open reading frames, for example if the inventive mRNA encodes for two or more antigenic peptides or proteins. An IRES-sequence may be particularly helpful if the mRNA is a bi- or multicistronic mRNA.

Additionally, the inventive mRNA may be prepared using any method known in the art, including synthetic methods such as e.g. solid phase synthesis, as well as in vitro methods, such as in vitro transcription reactions.

According to one embodiment of the present invention the mRNA comprising a coding region, encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV) or a fragment, variant or derivative thereof may be administered naked without being associated with any further vehicle, transfection or complexation agent for increasing the transfection efficiency and/or the immunostimulatory properties of the inventive mRNA or of further comprised nucleic acid.

In a preferred embodiment, the inventive mRNA may be formulated together with a cationic or polycationic compound and/or with a polymeric carrier. Accordingly, in a further embodiment of the invention it is preferred that the inventive mRNA or any other nucleic acid comprised in the inventive pharmaceutical composition or vaccine is associated with or complexed with a cationic or polycationic compound or a polymeric carrier, optionally in a weight ratio selected from a range of about 6:1 (w/w) to about 0.25:1 (w/w), more preferably from about 5:1 (w/w) to about 0.5:1 (w/w), even more preferably of about 4:1 (w/w) to about 1:1 (w/w) or of about 3:1 (w/w) to about 1:1 (w/w), and most preferably a ratio of about 3:1 (w/w) to about 2:1 (w/w) of mRNA or nucleic acid to cationic or polycationic compound and/or with a polymeric carrier; or optionally in a nitrogen/phosphate ratio of mRNA or nucleic acid to cationic or polycationic compound and/or polymeric carrier in the range of about 0.1-10, preferably in a range of about 0.3-4 or 0.3-1, and most preferably in a range of about 0.5-1 or 0.7-1, and even most preferably in a range of about 0.3-0.9 or 0.5-0.9.

Thereby, the inventive mRNA or any other nucleic acid comprised in the inventive pharmaceutical composition or vaccine can also be associated with a vehicle, transfection or complexation agent for increasing the transfection efficiency and/or the immunostimulatory properties of the inventive mRNA or of optionally comprised further included nucleic acids.

Cationic or polycationic compounds, being particularly preferred agents in this context include protamine, nucleoline, spermine or spermidine, or other cationic peptides or proteins, such as poly-L-lysine (PLL), poly-arginine, basic polypeptides, cell penetrating peptides (CPPs), including HIV-binding peptides, HIV-1 Tat (HIV), Tat-derived peptides, Penetratin, VP22 derived or analog peptides, HSV VP22 (Herpes simplex), MAP, KALA or protein transduction domains (PTDs), PpT620, prolin-rich peptides, arginine-rich peptides, lysine-rich peptides, MPG-peptide(s), Pep-1, L-oligomers, Calcitonin peptide(s), Antennapedia-derived peptides (particularly from Drosophila antennapedia), pAntp, pIsl, FGF, Lactoferrin, Transportan, Buforin-2, Bac715-24, SynB, SynB(1), pVEC, hCT-derived peptides, SAP, or histones.

In this context, protamine is particularly preferred.

Additionally, preferred cationic or polycationic proteins or peptides may be selected from the following proteins or peptides having the following total formula (III): (Arg)_(l);(Lys)_(m);(His)_(n);(Orn)_(o);(Xaa)_(x),  (formula (III))

wherein l+m+n+o+x=8-15, and 1, m, n or o independently of each other may be any number selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, provided that the overall content of Arg, Lys, His and Orn represents at least 50% of all amino acids of the oligopeptide; and Xaa may be any amino acid selected from native (=naturally occurring) or non-native amino acids except of Arg, Lys, His or Orn; and x may be any number selected from 0, 1, 2, 3 or 4, provided, that the overall content of Xaa does not exceed 50% of all amino acids of the oligopeptide. Particularly preferred cationic peptides in this context are e.g. Arg₇, Arg₈, Arg₉, H₃R₉, R₉H₃, H₃R₉H₃, YSSR₉SSY, (RKH)₄, Y(RKH)₂R, etc. In this context the disclosure of WO 2009/030481 is incorporated herewith by reference.

Further preferred cationic or polycationic compounds, which can be used as transfection or complexation agent may include cationic polysaccharides, for example chitosan, polybrene, cationic polymers, e.g. polyethyleneimine (PEI), cationic lipids, e.g. DOTMA: [1-(2,3-sioleyloxy)propyl)]-N,N,N-trimethylammonium chloride, DMRIE, di-C14-amidine, DOTIM, SAINT, DC-Chol, BGTC, CTAP, DOPC, DODAP, DOPE: Dioleyl phosphatidylethanol-amine, DOSPA, DODAB, DOIC, DMEPC, DOGS: Dioctadecylamidoglicylspermin, DIMRI: Dimyristo-oxypropyl dimethyl hydroxyethyl ammonium bromide, DOTAP: dioleoyloxy-3-(trim ethylammonio)propane, DC-6-14: O,O-ditetradecanoyl-N-(α-trimethylammonioacetyl)diethanolamine chloride, CLIP1: rac-[(2,3-dioctadecyloxypropyl)(2-hydroxyethyl)]-dimethylammonium chloride, CLIP6: rac-[2(2,3-dihexadecyloxypropyl-oxymethyloxy)ethyl]trimethylammonium, CLIPS: rac-[2(2,3-dihexadecyloxypropyl-oxysuccinyloxy)ethyl]-trimethylammonium, oligofectamine, or cationic or polycationic polymers, e.g. modified polyaminoacids, such as β-aminoacid-polymers or reversed polyamides, etc., modified polyethylenes, such as PVP (poly(N-ethyl-4-vinylpyridinium bromide)), etc., modified acrylates, such as pDMAEMA (poly(dimethylaminoethyl methylacrylate)), etc., modified amidoamines such as pAMAM (poly(amidoamine)), etc., modified polybetaaminoester (PBAE), such as diamine end modified 1,4 butanediol diacrylate-co-5-amino-1-pentanol polymers, etc., dendrimers, such as polypropylamine dendrimers or pAMAM based dendrimers, etc., polyimine(s), such as PEI: poly(ethyleneimine), poly(propyleneimine), etc., polyallylamine, sugar backbone based polymers, such as cyclodextrin based polymers, dextran based polymers, chitosan, etc., silan backbone based polymers, such as PMOXA-PDMS copolymers, etc., blockpolymers consisting of a combination of one or more cationic blocks (e.g. selected from a cationic polymer as mentioned above) and of one or more hydrophilic or hydrophobic blocks (e.g. polyethyleneglycole); etc.

A polymeric carrier used according to the invention might be a polymeric carrier formed by disulfide-crosslinked cationic components. The disulfide-crosslinked cationic components may be the same or different from each other. The polymeric carrier can also contain further components. It is also particularly preferred that the polymeric carrier used according to the present invention comprises mixtures of cationic peptides, proteins or polymers and optionally further components as defined herein, which are crosslinked by disulfide bonds as described herein. In this context, the disclosure of WO 2012/013326 is incorporated herewith by reference.

In this context, the cationic components, which form basis for the polymeric carrier by disulfide-crosslinkage, are typically selected from any suitable cationic or polycationic peptide, protein or polymer suitable for this purpose, particular any cationic or polycationic peptide, protein or polymer capable to complex an mRNA or a nucleic acid as defined according to the present invention, and thereby preferably condensing the mRNA or the nucleic acid. The cationic or polycationic peptide, protein or polymer, is preferably a linear molecule, however, branched cationic or polycationic peptides, proteins or polymers may also be used.

Every disulfide-crosslinking cationic or polycationic protein, peptide or polymer of the polymeric carrier, which may be used to complex the inventive mRNA or any further nucleic acid comprised in the inventive pharmaceutical composition or vaccine contains at least one —SH moiety, most preferably at least one cysteine residue or any further chemical group exhibiting an —SH moiety, capable to form a disulfide linkage upon condensation with at least one further cationic or polycationic protein, peptide or polymer as cationic component of the polymeric carrier as mentioned herein.

As defined above, the polymeric carrier, which may be used to complex the inventive mRNA or any further nucleic acid comprised in the inventive pharmaceutical composition or vaccine may be formed by disulfide-crosslinked cationic (or polycationic) components.

Preferably, such cationic or polycationic peptides or proteins or polymers of the polymeric carrier, which comprise or are additionally modified to comprise at least one —SH moiety, are selected from, proteins, peptides and polymers as defined above for complexation agent.

In a further particular embodiment, the polymeric carrier which may be used to complex the inventive mRNA or any further nucleic acid comprised in the inventive pharmaceutical composition or vaccine may be selected from a polymeric carrier molecule according to generic formula (IV): L-P¹—S—[S—P²—S]_(n)—S—P³-L  formula (IV)

wherein,

-   P¹ and P³ are different or identical to each other and represent a     linear or branched hydrophilic polymer chain, each P¹ and P³     exhibiting at least one —SH-moiety, capable to form a disulfide     linkage upon condensation with component P², or alternatively with     (AA), (AA)_(x), or [(AA)_(x)]_(z) if such components are used as a     linker between P¹ and P² or P³ and P²) and/or with further     components (e.g. (AA), (AA)_(x), [(AA)_(x)]_(z) or L), the linear or     branched hydrophilic polymer chain selected independent from each     other from polyethylene glycol (PEG),     poly-N-(2-hydroxypropyl)methacrylamide,     poly-2-(methacryloyloxy)ethyl phosphorylcholines, poly(hydroxyalkyl     L-asparagine), poly(2-(methacryloyloxy)ethyl phosphorylcholine),     hydroxyethylstarch or poly(hydroxyalkyl L-glutamine), wherein the     hydrophilic polymer chain exhibits a molecular weight of about 1 kDa     to about 100 kDa, preferably of about 2 kDa to about 25 kDa; or more     preferably of about 2 kDa to about 10 kDa, e.g. about 5 kDa to about     25 kDa or 5 kDa to about 10 kDa; -   P² is a cationic or polycationic peptide or protein, e.g. as defined     above for the polymeric carrier formed by disulfide-crosslinked     cationic components, and preferably having a length of about 3 to     about 100 amino acids, more preferably having a length of about 3 to     about 50 amino acids, even more preferably having a length of about     3 to about 25 amino acids, e.g. a length of about 3 to 10, 5 to 15,     10 to 20 or 15 to 25 amino acids, more preferably a length of about     5 to about 20 and even more preferably a length of about 10 to about     20; or     -   is a cationic or polycationic polymer, e.g. as defined above for         the polymeric carrier formed by disulfide-crosslinked cationic         components, typically having a molecular weight of about 0.5 kDa         to about 30 kDa, including a molecular weight of about 1 kDa to         about 20 kDa, even more preferably of about 1.5 kDa to about 10         kDa, or having a molecular weight of about 0.5 kDa to about 100         kDa, including a molecular weight of about 10 kDa to about 50         kDa, even more preferably of about 10 kDa to about 30 kDa;     -   each P² exhibiting at least two —SH-moieties, capable to form a         disulfide linkage upon condensation with further components P²         or component(s) P¹ and/or P³ or alternatively with further         components (e.g. (AA), (AA)_(x), or [(AA)_(x)]_(z)); -   —S—S— is a (reversible) disulfide bond (the brackets are omitted for     better readability), wherein S preferably represents sulphur or a     —SH carrying moiety, which has formed a (reversible) disulfide bond.     The (reversible) disulfide bond is preferably formed by condensation     of —SH-moieties of either components P¹ and P², P² and P², or P² and     P³, or optionally of further components as defined herein (e.g. L,     (AA), (AA), [(AA)_(x)]_(z), etc); The —SH-moiety may be part of the     structure of these components or added by a modification as defined     below; -   L is an optional ligand, which may be present or not, and may be     selected independent from the other from RGD, Transferrin, Folate, a     signal peptide or signal sequence, a localization signal or     sequence, a nuclear localization signal or sequence (NLS), an     antibody, a cell penetrating peptide, (e.g. TAT or KALA), a ligand     of a receptor (e.g. cytokines, hormones, growth factors etc), small     molecules (e.g. carbohydrates like mannose or galactose or synthetic     ligands), small molecule agonists, inhibitors or antagonists of     receptors (e.g. RGD peptidomimetic analogues), or any further     protein as defined herein, etc.; -   n is an integer, typically selected from a range of about 1 to 50,     preferably from a range of about 1, 2 or 3 to 30, more preferably     from a range of about 1, 2, 3, 4, or 5 to 25, or a range of about 1,     2, 3, 4, or 5 to 20, or a range of about 1, 2, 3, 4, or 5 to 15, or     a range of about 1, 2, 3, 4, or 5 to 10, including e.g. a range of     about 4 to 9, 4 to 10, 3 to 20, 4 to 20, 5 to 20, or 10 to 20, or a     range of about 3 to 15, 4 to 15, 5 to 15, or 10 to 15, or a range of     about 6 to 11 or 7 to 10. Most preferably, n is in a range of about     1, 2, 3, 4, or 5 to 10, more preferably in a range of about 1, 2, 3,     or 4 to 9, in a range of about 1, 2, 3, or 4 to 8, or in a range of     about 1, 2, or 3 to 7.

In this context the disclosure of WO 2011/026641 is incorporated herewith by reference. Each of hydrophilic polymers P¹ and P³ typically exhibits at least one —SH-moiety, wherein the at least one —SH-moiety is capable to form a disulfide linkage upon reaction with component P² or with component (AA) or (AA)_(x), if used as linker between P¹ and P² or P³ and P² as defined below and optionally with a further component, e.g. L and/or (AA) or (AA)_(x), e.g. if two or more —SH-moieties are contained. The following subformulae “P¹—S—S—P²” and “P²—S—S—P³” within generic formula (V) above (the brackets are omitted for better readability), wherein any of S, P¹ and P³ are as defined herein, typically represent a situation, wherein one-SH-moiety of hydrophilic polymers P¹ and P³ was condensed with one —SH-moiety of component P² of generic formula (V) above, wherein both sulphurs of these —SH-moieties form a disulfide bond —S—S— as defined herein in formula (V). These —SH-moieties are typically provided by each of the hydrophilic polymers P¹ and P³, e.g. via an internal cysteine or any further (modified) amino acid or compound which carries a —SH moiety. Accordingly, the subformulae “P¹—S—S—P²” and “P²—S—S—P³” may also be written as “P¹-Cys-Cys-P²” and “P²-Cys-Cys-P³”, if the —SH— moiety is provided by a cysteine, wherein the term Cys-Cys represents two cysteines coupled via a disulfide bond, not via a peptide bond. In this case, the term “—S—S—” in these formulae may also be written as “—S-Cys”, as “-Cys-S” or as “-Cys-Cys-”. In this context, the term “-Cys-Cys-” does not represent a peptide bond but a linkage of two cysteines via their —SH-moieties to form a disulfide bond. Accordingly, the term “-Cys-Cys-” also may be understood generally as “-(Cys-S)—(S-Cys)-”, wherein in this specific case S indicates the sulphur of the —SH-moiety of cysteine. Likewise, the terms “—S-Cys” and “—Cys-S” indicate a disulfide bond between a —SH containing moiety and a cysteine, which may also be written as “—S—(S-Cys)” and “-(Cys-S)—S”. Alternatively, the hydrophilic polymers P¹ and P³ may be modified with a —SH moiety, preferably via a chemical reaction with a compound carrying a —SH moiety, such that each of the hydrophilic polymers P¹ and P³ carries at least one such —SH moiety. Such a compound carrying a —SH moiety may be e.g. an (additional) cysteine or any further (modified) amino acid, which carries a —SH moiety. Such a compound may also be any non-amino compound or moiety, which contains or allows to introduce a —SH moiety into hydrophilic polymers P¹ and P³ as defined herein. Such non-amino compounds may be attached to the hydrophilic polymers P¹ and P³ of formula (VI) of the polymeric carrier according to the present invention via chemical reactions or binding of compounds, e.g. by binding of a 3-thio propionic acid or thioimolane, by amide formation (e.g. carboxylic acids, sulphonic acids, amines, etc), by Michael addition (e.g. maleinimide moieties, □,□ unsatured carbonyls, etc), by click chemistry (e.g. azides or alkines), by alkene/alkine methatesis (e.g. alkenes or alkines), imine or hydrozone formation (aldehydes or ketons, hydrazins, hydroxylamins, amines), complexation reactions (avidin, biotin, protein G) or components which allow Sn-type substitution reactions (e.g. halogenalkans, thiols, alcohols, amines, hydrazines, hydrazides, sulphonic acid esters, oxyphosphonium salts) or other chemical moieties which can be utilized in the attachment of further components. A particularly preferred PEG derivate in this context is alpha-Methoxy-omega-mercapto poly(ethylene glycol). In each case, the SH-moiety, e.g. of a cysteine or of any further (modified) amino acid or compound, may be present at the terminal ends or internally at any position of hydrophilic polymers P¹ and P³. As defined herein, each of hydrophilic polymers P¹ and P³ typically exhibits at least one —SH-moiety preferably at one terminal end, but may also contain two or even more —SH-moieties, which may be used to additionally attach further components as defined herein, preferably further functional peptides or proteins e.g. a ligand, an amino acid component (AA) or (AA)_(x), antibodies, cell penetrating peptides or enhancer peptides (e.g. TAT, KALA), etc.

In this context, it is particularly preferred that the inventive mRNA is complexed at least partially with a cationic or polycationic compound and/or a polymeric carrier, preferably cationic proteins or peptides. In this context the disclosure of WO 2010/037539 and WO 2012/113513 is incorporated herewith by reference. Partially means that only a part of the inventive mRNA is complexed with a cationic compound and that the rest of the inventive mRNA is (comprised in the inventive pharmaceutical composition or vaccine) in uncomplexed form (“free”). Preferably the ratio of complexed mRNA to: free mRNA (in the inventive pharmaceutical composition or vaccine) is selected from a range of about 5:1 (w/w) to about 1:10 (w/w), more preferably from a range of about 4:1 (w/w) to about 1:8 (w/w), even more preferably from a range of about 3:1 (w/w) to about 1:5 (w/w) or 1:3 (w/w), and most preferably the ratio of complexed mRNA to free mRNA in the inventive pharmaceutical composition or vaccine is selected from a ratio of about 1:1 (w/w).

The complexed mRNA in the inventive pharmaceutical composition or vaccine, is preferably prepared according to a first step by complexing the inventive mRNA with a cationic or polycationic compound and/or with a polymeric carrier, preferably as defined herein, in a specific ratio to form a stable complex. In this context, it is highly preferable, that no free cationic or polycationic compound or polymeric carrier or only a negligibly small amount thereof remains in the component of the complexed mRNA after complexing the mRNA. Accordingly, the ratio of the mRNA and the cationic or polycationic compound and/or the polymeric carrier in the component of the complexed mRNA is typically selected in a range that the mRNA is entirely complexed and no free cationic or polycationic compound or polymeric carrier or only a negligibly small amount thereof remains in the composition.

Preferably the ratio of the mRNA to the cationic or polycationic compound and/or the polymeric carrier, preferably as defined herein, is selected from a range of about 6:1 (w/w) to about 0.25:1 (w/w), more preferably from about 5:1 (w/w) to about 0.5:1 (w/w), even more preferably of about 4:1 (w/w) to about 1:1 (w/w) or of about 3:1 (w/w) to about 1:1 (w/w), and most preferably a ratio of about 3:1 (w/w) to about 2:1 (w/w). Alternatively, the ratio of the mRNA to the cationic or polycationic compound and/or the polymeric carrier, preferably as defined herein, in the component of the complexed mRNA, may also be calculated on the basis of the nitrogen/phosphate ratio (N/P-ratio) of the entire complex. In the context of the present invention, an N/P-ratio is preferably in the range of about 0.1-10, preferably in a range of about 0.3-4 and most preferably in a range of about 0.5-2 or 0.7-2 regarding the ratio of mRNA: cationic or polycationic compound and/or polymeric carrier, preferably as defined herein, in the complex, and most preferably in a range of about 0.7-1,5, 0.5-1 or 0.7-1, and even most preferably in a range of about 0.3-0.9 or 0.5-0.9, preferably provided that the cationic or polycationic compound in the complex is a cationic or polycationic cationic or polycationic protein or peptide and/or the polymeric carrier as defined above. In this specific embodiment the complexed mRNA is also encompassed in the term “adjuvant component”.

In a further aspect, the invention provides for a composition comprising a plurality or more than one, preferably 2 to 10, more preferably 2 to 5, most preferably 2 to 4 of the inventive mRNA sequences as defined herein. These inventive compositions comprise more than one inventive mRNA sequences, preferably encoding different peptides or proteins which comprise preferably different pathogenic antigens or fragments, variants or derivatives thereof. Particularly preferred in this context is that at least one mRNA sequence encodes at least one antigenic peptide or protein derived from the fusion protein F of Respiratory syncytial virus (RSV) and that at least one mRNA sequence encodes at least one antigenic peptide or protein derived from another antigen of Respiratory syncytial virus (RSV), particularly of nucleoprotein N or M2-1 protein. Further particularly preferred combinations of antigens are in this context:

-   -   F+G (serotype A)+G (serotype B)     -   F+G (serotype A)+G (serotype B)+M2-1     -   F+G (serotype A)+G (serotype B)+N     -   F+G (serotype A)+G (serotype B)+N+M2-1     -   F+M2-1+N     -   F+M2-1     -   F+N     -   F+G (serotype A)+G (serotype B)+N+M2-1+P+M2-2+M+L     -   F+G (serotype A)+G (serotype B)+N+M2-1+P+M2-2+M     -   F+G (serotype A)+G (serotype B)+N+M2-1+P+M2-2+L     -   F+G (serotype A)+G (serotype B)+N+M2-1+P+M+L     -   F+G (serotype A)+G (serotype B)+N+M2-1+M2-2+M+L     -   F+G (serotype A)+G (serotype B)+N+P+M2-2+M+L     -   F+G (serotype A)+G (serotype B)+M2-1+P+M2-2+M+L

Accordingly, in a further particular preferred aspect, the present invention also provides a pharmaceutical composition, comprising at least one inventive mRNA sequence as defined herein or an inventive composition comprising a plurality of inventive mRNA sequences as defined herein and optionally a pharmaceutically acceptable carrier and/or vehicle.

As a first ingredient, the inventive pharmaceutical composition comprises at least one inventive mRNA sequence as defined herein.

As a second ingredient, the inventive pharmaceutical composition may optionally comprise at least one additional pharmaceutically active component. A pharmaceutically active component in this connection is a compound that has a therapeutic effect to heal, ameliorate or prevent a particular indication or disease as mentioned herein, preferably RSV infections. Such compounds include, without implying any limitation, peptides or proteins, preferably as defined herein, nucleic acids, preferably as defined herein, (therapeutically active) low molecular weight organic or inorganic compounds (molecular weight less than 5000, preferably less than 1000), sugars, antigens or antibodies, preferably as defined herein, therapeutic agents already known in the prior art, antigenic cells, antigenic cellular fragments, cellular fractions; cell wall components (e.g. polysaccharides), modified, attenuated or de-activated (e.g. chemically or by irradiation) pathogens (virus, bacteria etc.), adjuvants, preferably as defined herein, etc. Particularly preferred in this context are RSV vaccines, or RSV immune globulines, e.g. Palivizumab (Synagis®).

The inventive pharmaceutical composition may be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir. The term parenteral as used herein includes subcutaneous, intravenous, intramuscular, intra-articular, intra-synovial, intrasternal, intrathecal, intrahepatic, intralesional, intracranial, transdermal, intradermal, intrapulmonal, intraperitoneal, intracardial, intraarterial, and sublingual injection or infusion techniques.

Particularly preferred is intradermal and intramuscular injection. Sterile injectable forms of the inventive pharmaceutical compositions may be aqueous or oleaginous suspension. These suspensions may be formulated according to techniques known in the art using suitable dispersing or wetting agents and suspending agents.

In a preferred embodiment, the inventive pharmaceutical composition is administered via intradermal or intramuscular injection, preferably by using conventional needle-based injection technique or by using a needle-free system, e.g. jet injection. In a further preferred embodiment, the inventive pharmaceutical composition may be administered by jet injection as defined herein. Preferably, the inventive pharmaceutical composition may be administered intramuscularly by jet injection. According to another embodiment, the pharmaceutical composition is administered intradermally via jet injection.

In a preferred embodiment, the pharmaceutical composition may be administered once, twice or three times, preferably by intradermal or intramuscular injection, preferably by jet injection. According to a certain embodiment, a single administration of the inventive pharmaceutical composition, preferably via intradermal or intramuscular injection, preferably by using jet injection, is sufficient for eliciting an immune response against the at least one antigen encoded by the mRNA sequence according to the invention. In a preferred embodiment, the single administration of the pharmaceutical composition elicits an immune response resulting in virus neutralisation. In this context, one single intradermal or intramuscular injection of the pharmaceutical composition is particularly preferred. Preferably, further administrations of the pharmaceutical composition may optionally be carried out in order to enhance and/or prolong the immune response.

According to a specific embodiment, the inventive pharmaceutical composition may comprise an adjuvant. In this context, an adjuvant may be understood as any compound, which is suitable to initiate or increase an immune response of the innate immune system, i.e. a non-specific immune response. With other words, when administered, the inventive pharmaceutical composition preferably elicits an innate immune response due to the adjuvant, optionally contained therein. Preferably, such an adjuvant may be selected from an adjuvant known to a skilled person and suitable for the present case, i.e. supporting the induction of an innate immune response in a mammal, e.g. an adjuvant protein as defined above or an adjuvant as defined in the following.

Particularly preferred as adjuvants suitable for depot and delivery are cationic or polycationic compounds as defined above for the inventive mRNA sequence as vehicle, transfection or complexation agent.

Furthermore, the inventive pharmaceutical composition may comprise one or more additional adjuvants, which are suitable to initiate or increase an immune response of the innate immune system, i.e. a non-specific immune response, particularly by binding to pathogen-associated molecular patterns (PAMPs). With other words, when administered, the pharmaceutical composition or vaccine preferably elicits an innate immune response due to the adjuvant, optionally contained therein. Preferably, such an adjuvant may be selected from an adjuvant known to a skilled person and suitable for the present case, i.e. supporting the induction of an innate immune response in a mammal, e.g. an adjuvant protein as defined above or an adjuvant as defined in the following. According to one embodiment such an adjuvant may be selected from an adjuvant as defined above.

Also such an adjuvant may be selected from any adjuvant known to a skilled person and suitable for the present case, i.e. supporting the induction of an innate immune response in a mammal and/or suitable for depot and delivery of the components of the inventive pharmaceutical composition or vaccine. Preferred as adjuvants suitable for depot and delivery are cationic or polycationic compounds as defined above. Likewise, the adjuvant may be selected from the group consisting of, e.g., cationic or polycationic compounds as defined above, from chitosan, TDM, MDP, muramyl dipeptide, pluronics, alum solution, aluminium hydroxide, ADJUMER™ (polyphosphazene); aluminium phosphate gel; glucans from algae; algammulin; aluminium hydroxide gel (alum); highly protein-adsorbing aluminium hydroxide gel; low viscosity aluminium hydroxide gel; AF or SPT (emulsion of squalane (5%), Tween 80 (0.2%), Pluronic L121 (1.25%), phosphate-buffered saline, pH 7.4); AVRIDINE™ (propanediamine); BAY R1005™ ((N-(2-deoxy-2-L-leucylaminob-D-glucopyranosyl)-N-octadecyl-dodecanoyl-amide hydroacetate); CALCITRIOL™ (1-alpha,25-dihydroxy-vitamin D3); calcium phosphate gel; CAP™ (calcium phosphate nanoparticles); cholera holotoxin, cholera-toxin-A1-protein-A-D-fragment fusion protein, sub-unit B of the cholera toxin; CRL 1005 (block copolymer P1205); cytokine-containing liposomes; DDA (dimethyldioctadecylammonium bromide); DHEA (dehydroepiandrosterone); DMPC (dimyristoylphosphatidylcholine); DMPG (dimyristoylphosphatidylglycerol); DOC/alum complex (deoxycholic acid sodium salt); Freund's complete adjuvant; Freund's incomplete adjuvant; gamma inulin; Gerbu adjuvant (mixture of: i) N-acetylglucosaminyl-(P1-4)-N-acetylmuramyl-L-alanyl-D35 glutamine (GMDP), ii) dimethyldioctadecylammonium chloride (DDA), iii) zinc-L-proline salt complex (ZnPro-8); GM-CSF); GMDP (N-acetylglucosaminyl-(b1-4)-N-acetylmuramyl-L47 alanyl-D-isoglutamine); imiquimod (1-(2-methypropyl)-1H-imidazo[4,5-c]quinoline-4-amine); ImmTher™ (N-acetylglucosaminyl-N-acetylmuramyl-L-Ala-D-isoGlu-L-Ala-glycerol dipalmitate); DRVs (immunoliposomes prepared from dehydration-rehydration vesicles); interferongamma; interleukin-1beta; interleukin-2; interleukin-7; interleukin-12; ISCOMS™; ISCOPREP 7.0.3.™; liposomes; LOXORIBINE™ (7-allyl-8-oxoguanosine); LT 5 oral adjuvant (E. coli labile enterotoxin-protoxin); microspheres and microparticles of any composition; MF59™; (squalenewater emulsion); MONTANIDE ISA 51™ (purified incomplete Freund's adjuvant); MONTANIDE ISA 720™ (metabolisable oil adjuvant); MPL™ (3-Q-desacyl-4′-monophosphoryl lipid A); MTP-PE and MTP-PE liposomes ((N-acetyl-L-alanyl-D-isoglutaminyl-L-alanine-2-(1,2-dipalmitoyl-sn-glycero-3-(hydroxyphosphoryloxy))-ethylamide, monosodium salt); MURAMETIDE™ (Nac-Mur-L-Ala-D-Gln-OCH3); MURAPALMITINE™ and DMURAPALMITINE™ (Nac-Mur-L-Thr-D-isoGIn-sn-glyceroldipalmitoyl); NAGO (neuraminidase-galactose oxidase); nanospheres or nanoparticles of any composition; NISVs (non-ionic surfactant vesicles); PLEURAN™ (□β-glucan); PLGA, PGA and PLA (homo- and co-polymers of lactic acid and glycolic acid; microspheres/nanospheres); PLURONIC L121™; PMMA (polymethylmethacrylate); PODDS™ (proteinoid microspheres); polyethylene carbamate derivatives; poly-rA: poly-rU (polyadenylic acid-polyuridylic acid complex); polysorbate 80 (Tween 80); protein cochleates (Avanti Polar Lipids, Inc., Alabaster, Ala.); STIMULON™ (QS-21); Quil-A (Quil-A saponin); S-28463 (4-amino-otec-dimethyl-2-ethoxymethyl-1H-imidazo[4,5-c]quinoline-1-ethanol); SAF-1™ (“Syntex adjuvant formulation”); Sendai proteoliposomes and Sendai containing lipid matrices; Span-85 (sorbitan trioleate); Specol (emulsion of Marcol 52, Span 85 and Tween 85); squalene or Robane® (2,6,10,15,19,23-hexamethyltetracosan and 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexane); stearyltyrosine (octadecyltyrosine hydrochloride); Theramid® (N-acetylglucosaminyl-N-acetylmuramyl-L-Ala-D-isoGlu-L-Aladipalmitoxypropylamide); Theronyl-MDP (Termurtide™ or [thr 1]-MDP; N-acetylmuramyl-Lthreonyl-D-isoglutamine); Ty particles (Ty-VLPs or virus-like particles); Walter-Reed liposomes (liposomes containing lipid A adsorbed on aluminium hydroxide), and lipopeptides, including Pam3Cys, in particular aluminium salts, such as Adju-phos, Alhydrogel, Rehydragel; emulsions, including CFA, SAF, IFA, MF59, Provax, TiterMax, Montanide, Vaxfectin; copolymers, including Optivax (CRL1005), L121, Poloaxmer4010), etc.; liposomes, including Stealth, cochleates, including BIORAL; plant derived adjuvants, including QS21, Quil A, Iscomatrix, ISCOM; adjuvants suitable for costimulation including Tomatine, biopolymers, including PLG, PMM, Inulin, microbe derived adjuvants, including Romurtide, DETOX, MPL, CWS, Mannose, CpG nucleic acid sequences, CpG7909, ligands of human TLR 1-10, ligands of murine TLR 1-13, ISS-1018, 35 IC31, Imidazoquinolines, Ampligen, Ribi529, IMOxine, IRIVs, VLPs, cholera toxin, heat-labile toxin, Pam3Cys, Flagellin, GPI anchor, LNFPIII/Lewis X, antimicrobial peptides, UC-1V150, RSV fusion protein, cdiGMP; and adjuvants suitable as antagonists including CGRP neuropeptide.

Particularly preferred, an adjuvant may be selected from adjuvants, which support induction of a Th1-immune response or maturation of naïve T-cells, such as GM-CSF, IL-12, IFNg, any immunostimulatory nucleic acid as defined above, preferably an immunostimulatory RNA, CpG DNA, etc.

In a further preferred embodiment, it is also possible that the inventive pharmaceutical composition contains besides the antigen-providing mRNA further components, which are selected from the group comprising: further antigens or further antigen-providing nucleic acids; a further immunotherapeutic agent; one or more auxiliary substances; or any further compound, which is known to be immunostimulating due to its binding affinity (as ligands) to human Toll-like receptors; and/or an adjuvant nucleic acid, preferably an immunostimulatory RNA (isRNA).

The inventive pharmaceutical composition can additionally contain one or more auxiliary substances in order to increase its immunogenicity or immunostimulatory capacity, if desired. A synergistic action of the inventive mRNA sequence as defined herein and of an auxiliary substance, which may be optionally contained in the inventive pharmaceutical composition, is preferably achieved thereby. Depending on the various types of auxiliary substances, various mechanisms can come into consideration in this respect. For example, compounds that permit the maturation of dendritic cells (DCs), for example lipopolysaccharides, TNF-alpha or CD40 ligand, form a first class of suitable auxiliary substances. In general, it is possible to use as auxiliary substance any agent that influences the immune system in the manner of a “danger signal” (LPS, GP96, etc.) or cytokines, such as GM-CFS, which allow an immune response to be enhanced and/or influenced in a targeted manner. Particularly preferred auxiliary substances are cytokines, such as monokines, lymphokines, interleukins or chemokines, that further promote the innate immune response, such as IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-14, IL-15, IL-16, IL-17, IL-18, IL-19, IL-20, IL-21, IL-22, IL-23, IL-24, IL-25, IL-26, IL-27, IL-28, IL-29, IL-30, IL-31, IL-32, IL-33, IFN-alpha, IFN-beta, IFN-gamma, GM-CSF, G-CSF, M-CSF, LT-beta or TNF-alpha, growth factors, such as hGH.

Further additives, which may be included in the inventive pharmaceutical composition, are emulsifiers, such as, for example, Tween®; wetting agents, such as, for example, sodium lauryl sulfate; colouring agents; taste-imparting agents, pharmaceutical carriers; tablet-forming agents; stabilizers; antioxidants; preservatives.

The inventive pharmaceutical composition can also additionally contain any further compound, which is known to be immunostimulating due to its binding affinity (as ligands) to human Toll-like receptors TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, or due to its binding affinity (as ligands) to murine Toll-like receptors TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12 or TLR13.

In this context, it is particularly preferred that the optionally comprised adjuvant component comprises the same inventive mRNA as comprised in the inventive pharmaceutical composition as antigen-providing mRNA e.g. mRNA coding for an antigenic peptide or protein of RSV infections Respiratory syncytial virus (RSV) or fragments, variants or derivatives thereof.

Despite, the inventive pharmaceutical composition may comprise further components for facilitating administration and uptake of components of the pharmaceutical composition. Such further components may be an appropriate carrier or vehicle, additional adjuvants for supporting any immune response, antibacterial and/or antiviral agents.

Accordingly, in a further embodiment, the inventive pharmaceutical composition furthermore comprises a pharmaceutically acceptable carrier and/or vehicle.

Such a pharmaceutically acceptable carrier typically includes the liquid or non-liquid basis of a composition comprising the components of the inventive pharmaceutical composition. If the composition is provided in liquid form, the carrier will typically be pyrogen-free water; isotonic saline or buffered (aqueous) solutions, e.g. phosphate, citrate etc. buffered solutions. The injection buffer may be hypertonic, isotonic or hypotonic with reference to the specific reference medium, i.e. the buffer may have a higher, identical or lower salt content with reference to the specific reference medium, wherein preferably such concentrations of the afore mentioned salts may be used, which do not lead to damage of cells due to osmosis or other concentration effects. Reference media are e.g. liquids occurring in “in vivo” methods, such as blood, lymph, cytosolic liquids, or other body liquids, or e.g. liquids, which may be used as reference media in “in vitro” methods, such as common buffers or liquids. Such common buffers or liquids are known to a skilled person. Ringer-Lactate solution is particularly preferred as a liquid basis.

However, one or more compatible solid or liquid fillers or diluents or encapsulating compounds, which are suitable for administration to a patient to be treated, may be used as well for the pharmaceutical composition according to the invention. The term “compatible” as used here means that these constituents of the inventive pharmaceutical composition are capable of being mixed with the components of the inventive pharmaceutical composition in such a manner that no interaction occurs which would substantially reduce the pharmaceutical effectiveness of the pharmaceutical composition under typical use conditions.

A further component of the inventive pharmaceutical composition may be an immunotherapeutic agent that can be selected from immunoglobulins, preferably IgGs, monoclonal or polyclonal antibodies, polyclonal serum or sera, etc, most preferably immunoglobulins directed against Respiratory syncytial virus (RSV), e.g. Palivizumab. Preferably, such a further immunotherapeutic agent may be provided as a peptide/protein or may be encoded by a nucleic acid, preferably by a DNA or an RNA, more preferably an mRNA. Such an immunotherapeutic agent allows providing passive vaccination additional to active vaccination triggered by the inventive antigen-providing mRNA.

Furthermore, in a specific embodiment, additionally to the antigen-providing mRNA further antigens can be included in the inventive pharmaceutical composition and are typically substances such as cells, cell lysates, viruses, attenuated viruses, inactivated viruses, proteins, peptides, nucleic acids or other bio- or macromolecules or fragments thereof. Preferably, antigens may be proteins and peptides or fragments thereof, such as epitopes of those proteins or peptides, preferably having 5 to 15, more preferably 6 to 9, amino acids. Particularly, said proteins, peptides or epitopes may be derived from the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV), or from fragments, variants or derivatives thereof. Further, antigens may also comprise any other biomolecule, e.g., lipids, carbohydrates, etc. Preferably, the antigen is a protein or (poly-) peptide antigen, a nucleic acid, a nucleic acid encoding a protein or (poly-) peptide antigen, a polysaccharide antigen, a polysaccharide conjugate antigen, a lipid antigen, a glycolipid antigen, a carbohydrate antigen, a bacterium, a cell (vaccine), or killed or attenuated viruses.

The inventive pharmaceutical composition or vaccine as defined herein may furthermore comprise further additives or additional compounds. Further additives, which may be included in the pharmaceutical composition, are emulsifiers, such as, for example, Tween®; wetting agents, such as, for example, sodium lauryl sulfate; colouring agents; taste-imparting agents, pharmaceutical carriers; tablet-forming agents; stabilizers; antioxidants; preservatives, RNase inhibitors and/or an anti-bacterial agent or an anti-viral agent. Additionally the inventive pharmaceutical composition may comprise small interfering RNA (siRNA) directed against genes of Respiratory syncytial virus (RSV), e.g. siRNA directed against the gene encoding the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV). The inventive pharmaceutical composition typically comprises a “safe and effective amount” of the components of the inventive pharmaceutical composition, particularly of the inventive mRNA sequence(s) as defined herein. As used herein, a “safe and effective amount” means an amount of the inventive mRNA sequence(s) as defined herein as such that is sufficient to significantly induce a positive modification of a disease or disorder or to prevent a disease, preferably RSV infections as defined herein. At the same time, however, a “safe and effective amount” is small enough to avoid serious side-effects and to permit a sensible relationship between advantage and risk. The determination of these limits typically lies within the scope of sensible medical judgment.

The inventive pharmaceutical composition may be used for human and also for veterinary medical purposes, preferably for human medical purposes, as a pharmaceutical composition in general or as a vaccine.

According to another particularly preferred aspect, the inventive pharmaceutical composition (or the inventive mRNA sequence as defined herein or the inventive composition comprising a plurality of inventive mRNA sequences as defined herein) may be provided or used as a vaccine. Typically, such a vaccine is as defined above for pharmaceutical compositions. Additionally, such a vaccine typically contains the inventive mRNA sequence as defined herein or the inventive composition comprising a plurality of inventive mRNA sequences as defined herein.

The inventive vaccine may also comprise a pharmaceutically acceptable carrier, adjuvant, and/or vehicle as defined herein for the inventive pharmaceutical composition. In the specific context of the inventive vaccine, the choice of a pharmaceutically acceptable carrier is determined in principle by the manner in which the inventive vaccine is administered. The inventive vaccine can be administered, for example, systemically or locally. Routes for systemic administration in general include, for example, transdermal, oral, parenteral routes, including subcutaneous, intravenous, intramuscular, intraarterial, intradermal and intraperitoneal injections and/or intranasal administration routes. Routes for local administration in general include, for example, topical administration routes but also intradermal, transdermal, subcutaneous, or intramuscular injections or intralesional, intracranial, intrapulmonal, intracardial, and sublingual injections. More preferably, vaccines may be administered by an intradermal, subcutaneous, or intramuscular route. Inventive vaccines are therefore preferably formulated in liquid (or sometimes in solid) form.

In a preferred embodiment, the inventive vaccine is administered via intradermal or intramuscular injection, preferably by using conventional needle-based injection technique or by using a needle-free system, e.g. jet injection. In a further preferred embodiment, the inventive vaccine may be administered by jet injection as defined herein. Preferably, the inventive vaccine is administered intramuscularly by jet injection. According to another embodiment, the vaccine is administered intradermally via jet injection.

In a preferred embodiment, the vaccine may be administered once, twice or three times, preferably by intradermal or intramuscular injection, preferably by jet injection. According to a certain embodiment, a single administration of the inventive vaccine, preferably via intradermal or intramuscular injection, preferably by using jet injection, is sufficient for eliciting an immune response against the at least one antigen encoded by the mRNA sequence according to the invention. In a preferred embodiment, the single administration of the vaccine elicits an immune response resulting in virus neutralisation. In this context, one single intradermal or intramuscular injection of the vaccine is particularly preferred. Preferably, further administrations of the vaccine may optionally be carried out in order to enhance and/or prolong the immune response.

The inventive vaccine can additionally contain one or more auxiliary substances in order to increase its immunogenicity or immunostimulatory capacity, if desired. Particularly preferred are adjuvants as auxiliary substances or additives as defined for the pharmaceutical composition.

In a further aspect, the invention is directed to a kit or kit of parts comprising the components of the inventive mRNA sequence, the inventive composition comprising a plurality of inventive mRNA sequences, the inventive pharmaceutical composition or vaccine and optionally technical instructions with information on the administration and dosage of the components.

Beside the components of the inventive mRNA sequence, the inventive composition comprising a plurality of inventive mRNA sequences, the inventive pharmaceutical composition or vaccine the kit may additionally contain a pharmaceutically acceptable vehicle, an adjuvant and at least one further component as defined herein, as well as means for administration and technical instructions. The components of the inventive mRNA sequence, the inventive composition comprising a plurality of inventive mRNA sequences, the inventive pharmaceutical composition or vaccine and e.g. the adjuvant may be provided in lyophilized form. In a preferred embodiment, prior to use of the kit for vaccination, the provided vehicle is than added to the lyophilized components in a predetermined amount as written e.g. in the provided technical instructions. By doing so the inventive mRNA sequence, the inventive composition comprising a plurality of inventive mRNA sequences, the inventive pharmaceutical composition or vaccine, according to the above described aspects of the invention is provided that can afterwards be used in a method as described above, also.

The present invention furthermore provides several applications and uses of the inventive mRNA sequence as defined herein, of the inventive composition comprising a plurality of inventive mRNA sequences as defined herein, of the inventive pharmaceutical composition, of the inventive vaccine, all comprising the inventive mRNA sequence as defined herein or of kits comprising same.

In a further aspect, the invention provides an mRNA sequence encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV), or a fragment, variant or derivative thereof, and a composition, a pharmaceutical composition, a vaccine and a kit, all comprising the mRNA sequence for use in a method of prophylactic and/or therapeutic treatment of RSV infections. Consequently, in a further aspect, the present invention is directed to the first medical use of the inventive mRNA sequence, the inventive composition comprising a plurality of inventive mRNA sequences, the inventive pharmaceutical composition, the inventive vaccine, and the inventive kit as defined herein as a medicament. Particularly, the invention provides the use of an mRNA sequence encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV), or a fragment, variant or derivative thereof as defined above for the preparation of a medicament.

According to another aspect, the present invention is directed to the second medical use of the mRNA sequence encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV), or a fragment, variant or derivative thereof, as defined herein, optionally in form of a composition comprising a plurality of inventive mRNA sequences, a pharmaceutical composition or vaccine, kit or kit of parts, for the treatment of RSV infections as defined herein. Particularly, the mRNA sequence encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV), or a fragment, variant or derivative thereof to be used in a method as said above is a mRNA sequence formulated together with a pharmaceutically acceptable vehicle and an optionally additional adjuvant and an optionally additional further component as defined above e.g. a further antigen or a RSV immune globuline. In this context particularly the (prophylactic) treatment of infants, the elderly and immunocompromised patients is preferred. And even more preferred is the (prophylactic) treatment of pre-term infants and infants with chronic lung disease.

The inventive mRNA sequence may alternatively be provided such that it is administered for preventing or treating RSV infections by several doses, each dose containing the inventive mRNA sequence encoding at least one antigenic peptide or protein of RSV infections Respiratory syncytial virus (RSV), or a fragment, variant or derivative thereof, e.g. the first dose containing at least one mRNA encoding at least one antigenic peptide or protein derived from the fusion protein F (or fragments, variants or derivatives thereof) and the second dose containing at least one mRNA sequence encoding at least one antigenic peptide or protein derived from a different antigen of Respiratory syncytial virus (RSV), preferably from the nucleoprotein N (or fragments, variants or derivatives thereof), from the M2-1 protein or the glycoprotein G (or fragments, variants or derivatives thereof). By that embodiment, both doses are administered in a staggered way, i.e. subsequently, shortly one after the other, e.g. within less than 10 minutes, preferably less than 2 minutes, and at the same site of the body to achieve the same immunological effect as for administration of one single composition containing both, e.g. the mRNA encoding the fusion protein F and the mRNA encoding the nucleoprotein N.

According to a specific embodiment, the inventive mRNA sequence, or the inventive pharmaceutical composition or vaccine may be administered to the patient as a single dose. In certain embodiments, the inventive mRNA sequence or the inventive pharmaceutical composition or vaccine may be administered to a patient as a single dose followed by a second dose later and optionally even a third, fourth (or more) dose subsequent thereto etc. In accordance with this embodiment, booster inoculations with the inventive mRNA sequence or the inventive pharmaceutical composition or vaccine may be administered to a patient at specific time intervals, preferably as defined below, following the second (or third, fourth, etc.) inoculation. In this context, it is particularly preferred that several doses comprise the same mRNA sequence encoding the same antigenic peptide or protein of Respiratory syncytial virus (RSV), e.g. fusion protein F. In that embodiment the doses are given in a specific time period e.g. 20-30 days. For example for post-exposure prophylaxis at least 5 doses of the inventive mRNA sequence or inventive pharmaceutical composition or vaccine can be administered in 20-30 days.

In a preferred embodiment, inventive mRNA sequence, inventive pharmaceutical composition or vaccine is administered via intradermal or intramuscular injection, preferably by using conventional needle-based injection technique or by using a needle-free system, e.g. jet injection. In a further preferred embodiment, the inventive mRNA sequence, inventive pharmaceutical composition or vaccine may be administered by jet injection as defined herein. Preferably, the inventive mRNA sequence, inventive pharmaceutical composition or vaccine is administered intramuscularly by jet injection. According to another embodiment, the inventive mRNA sequence, inventive pharmaceutical composition or vaccine is administered intradermally via jet injection.

In a preferred embodiment, the inventive mRNA sequence, inventive pharmaceutical composition or vaccine may be administered once, twice or three times, preferably by intradermal or intramuscular injection, preferably by jet injection. According to a certain embodiment, a single administration of the inventive mRNA sequence, inventive pharmaceutical composition or vaccine, preferably via intradermal or intramuscular injection, preferably by using jet injection, is sufficient for eliciting an immune response against the at least one antigen encoded by the mRNA sequence according to the invention. In a preferred embodiment, the single administration of the inventive mRNA sequence, inventive pharmaceutical composition or vaccine elicits an immune response resulting in virus neutralisation. In this context, one single intradermal or intramuscular injection of the inventive mRNA sequence, inventive pharmaceutical composition or vaccine is particularly preferred. Preferably, further administrations of the inventive mRNA sequence, inventive pharmaceutical composition or vaccine may optionally be carried out in order to enhance and/or prolong the immune response.

In certain embodiments, such booster inoculations with the inventive mRNA sequence or inventive pharmaceutical composition or vaccine may utilize an additional compound or component as defined for the inventive mRNA sequence or inventive pharmaceutical composition or vaccine as defined herein.

According to a further aspect, the present invention also provides a method for expression of an encoded antigenic peptide or protein derived from the fusion protein F, the glycoprotein G, the short hydrophobic protein SH, the matrix protein M, the nucleoprotein N, the large polymerase L, the M2-1 protein, the M2-2 protein, the phosphoprotein P, the non-structural protein NS1 or the non-structural protein NS2 of Respiratory syncytial virus (RSV) comprising the steps, e.g. a) providing the inventive mRNA sequence as defined herein or the inventive composition comprising a plurality of inventive mRNA sequences as defined herein, b) applying or administering the inventive mRNA sequence as defined herein or the inventive composition comprising a plurality of inventive mRNA sequences as defined herein to an expression system, e.g. to a cell-free expression system, a cell (e.g. an expression host cell or a somatic cell), a tissue or an organism. The method may be applied for laboratory, for research, for diagnostic, for commercial production of peptides or proteins and/or for therapeutic purposes. In this context, typically after preparing the inventive mRNA sequence as defined herein or of the inventive composition comprising a plurality of inventive mRNA sequences as defined herein, it is typically applied or administered to a cell-free expression system, a cell (e.g. an expression host cell or a somatic cell), a tissue or an organism, e.g. in naked or complexed form or as a pharmaceutical composition or vaccine as described herein, preferably via transfection or by using any of the administration modes as described herein. The method may be carried out in vitro, in vivo or ex vivo. The method may furthermore be carried out in the context of the treatment of a specific disease, particularly in the treatment of infectious diseases, preferably RSV infections as defined herein.

In this context, in vitro is defined herein as transfection or transduction of the inventive mRNA as defined herein or of the inventive composition comprising a plurality of inventive mRNA sequences as defined herein into cells in culture outside of an organism; in vivo is defined herein as transfection or transduction of the inventive mRNA or of the inventive composition comprising a plurality of inventive mRNA sequences into cells by application of the inventive mRNA or of the inventive composition to the whole organism or individual and ex vivo is defined herein as transfection or transduction of the inventive mRNA or of the inventive composition comprising a plurality of inventive mRNA sequences into cells outside of an organism or individual and subsequent application of the transfected cells to the organism or individual.

Likewise, according to another aspect, the present invention also provides the use of the inventive mRNA sequence as defined herein or of the inventive composition comprising a plurality of inventive mRNA sequences as defined herein, preferably for diagnostic or therapeutic purposes, for expression of an encoded antigenic peptide or protein, e.g. by applying or administering the inventive mRNA sequence as defined herein or of the inventive composition comprising a plurality of inventive mRNA sequences as defined herein, e.g. to a cell-free expression system, a cell (e.g. an expression host cell or a somatic cell), a tissue or an organism. The use may be applied for laboratory, for research, for diagnostic for commercial production of peptides or proteins and/or for therapeutic purposes. In this context, typically after preparing the inventive mRNA sequence as defined herein or of the inventive composition comprising a plurality of inventive mRNA sequences as defined herein, it is typically applied or administered to a cell-free expression system, a cell (e.g. an expression host cell or a somatic cell), a tissue or an organism, preferably in naked form or complexed form, or as a pharmaceutical composition or vaccine as described herein, preferably via transfection or by using any of the administration modes as described herein. The use may be carried out in vitro, in vivo or ex vivo. The use may furthermore be carried out in the context of the treatment of a specific disease, particularly in the treatment of RSV infections.

In a further aspect, the invention provides a method of treatment or prophlaxis of RSV infections comprising the steps:

-   a) providing the inventive mRNA sequence, the composition comprising     a plurality of inventive mRNA sequences, the pharmaceutical     composition or the kit or kit of parts comprising the inventive mRNA     sequence as defined above; -   b) applying or administering the mRNA sequence, the composition, the     pharmaceutical composition or the kit or kit of parts to a tissue or     an organism; -   c) optionally administering RSV immune globuline.

Taken together, the invention provides in a certain aspect an mRNA sequence comprising a coding region encoding at least one antigenic peptide or protein of Respiratory syncytial virus (RSV). The inventive mRNA sequence is for use in a method of prophylactic and/or therapeutic treatment of infections caused by syncytial virus (RSV). Accordingly, the invention relates to an mRNA sequence as defined herein for use in a method of prophylactic and/or therapeutic treatment of RSV infections.

In the present invention, if not otherwise indicated, different features of alternatives and embodiments may be combined with each other, where suitable. Furthermore, the term “comprising” shall not be narrowly construed as being limited to “consisting of” only, if not specifically mentioned. Rather, in the context of the present invention, “consisting of” is an embodiment specifically contemplated by the inventors to fall under the scope of “comprising”, wherever “comprising” is used herein.

All publications, patents and patent applications cited in this specification are herein incorporated by reference as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claims.

BRIEF DESCRIPTION OF THE FIGURES

The figures shown in the following are merely illustrative and shall describe the present invention in a further way. These figures shall not be construed to limit the present invention thereto.

FIG. 1: G/C optimized mRNA sequence of R1691 coding for RSV-F protein of the RSV long strain (RSV-F long) as comprised in the RSV-F long mRNA vaccine (SEQ ID NO. 31).

FIG. 2: G/C optimized mRNA sequence of R2510 coding for RSV-F protein of the RSV long strain (RSV-F long) as comprised in the RSV-F long mRNA vaccine (SEQ ID NO. 32).

FIG. 3: G/C optimized mRNA sequence of R2821 coding for RSV-F del554-574 mutant protein of the RSV long strain (RSV-F long) (SEQ ID NO. 33).

FIG. 4: G/C optimized mRNA sequence of R2831 coding for RSV-N protein of the RSV long strain (RSV-F long) (SEQ ID NO. 34).

FIG. 5: G/C optimized mRNA sequence of R2833 coding for RSV-M2-1 protein of the RSV long strain (RSV-F long) (SEQ ID NO. 35).

FIGS. 6A-C: show that the RSV-F long mRNA vaccine induces antibody titers against the RSV-F protein comparable to those against inactivated RSV.

-   -   Female BALB/c mice were intradermally (i.d.) injected with the         RSV-F long mRNA vaccine (160 μg of R1691) or Ringer-Lactate         (RiLa buffer) as buffer control. One group was intramuscularly         (i.m.) injected with 10 μg of the inactivated RSV long vaccine.         All animals received boost injections on days 21 and 35, blood         samples were collected on day 49 for the determination of         antibody titers of pooled sera as described in Example 2.     -   As can be seen, the RSV-F long mRNA vaccine induces anti-F         protein antibodies of the IgG1 and IgG2a subclasses. Antibody         titers are displayed in the graph (n=5 mice/group).

FIG. 7: shows that the RSV-F long mRNA vaccine (R1691) induces a long-lived immune response in mice.

-   -   The experiment was performed as described in Example 3 and         antibody total IgG titers determined by ELISA.     -   As can be seen, the antibody titers are stable for at least         eleven months after the last boost vaccination.

FIGS. 8A-D: show that the RSV-F long mRNA vaccine (R1691) induces RSV Fusion (F) protein-specific multifunctional CD8⁺ T cells in mice.

-   -   The experiment was performed as described in Example 4 and T         cells were analysed by intracellular cytokine staining for the         antigen-specific induction of cytokines. Cells were stimulated         with a RSV-F peptide (stim. F; KYKNAVTEL) or a control influenza         HA peptide (stim. HA; IYSTVASSL). The line in the graph         represents the median value (n=5 mice/group).     -   As can be seen, the RSV-F long mRNA vaccine induces RSV         Fusion (F) protein-specific multifunctional CD8⁺ T cells in         contrast to the vaccine based on inactivated RSV which is not         able to induce F protein-specific CD8⁺ T cells.

FIGS. 9A-C: show that the RSV-N mRNA vaccine (R2831) induces Nucleoprotein (N)-specific multifunctional CD8⁺ T cells in mice.

-   -   The experiment was performed as described in Example 5 and T         cells were analysed by intracellular cytokine staining for the         antigen-specific induction of cytokines after stimulation with         ProMix RSV-N(15 mer peptides). The line in the graph represents         the median value (n=5 mice/group).     -   As can be seen, the RSV-N mRNA vaccine induces RSV Nucleoprotein         (N)-specific multifunctional CD8⁺ T cells in contrast to the         vaccine based on inactivated RSV which is not able to induce N         protein-specific CD8⁺ T cells.

FIGS. 10A-C: show that the RSV-N mRNA vaccine (R2831) induces Nucleoprotein (N)-specific multifunctional CD4⁺ T cells in mice.

-   -   The experiment was performed as described in Example 5 and T         cells were analysed by intracellular cytokine staining for the         antigen-specific induction of cytokines after stimulation with         ProMix RSV-N(15 mer peptides). The line in the graph represents         the median value (n=5 mice/group).     -   As can be seen, the RSV-N mRNA vaccine induces RSV Nucleoprotein         (N)-specific multifunctional CD4⁺ T cells in contrast to the         vaccine based on inactivated RSV which is not able to induce N         protein-specific CD4⁺ T cells.

FIGS. 11A-C: show that the RSV-M2-1 mRNA vaccine (R2833) induces M2-1-specific multifunctional CD8⁺ T cells in mice.

-   -   The experiment was performed as described in Example 5 and T         cells were analysed by intracellular cytokine staining for the         antigen-specific induction of cytokines after stimulation with a         M2-1 specific 9 mer peptide. The line in the graph represents         the median value (n=5 mice/group).     -   As can be seen, the RSV-M2-1 mRNA vaccine induces RSV         RSV-M2-1-specific multifunctional CD8⁺ T cells in contrast to         the vaccine based on inactivated RSV which is not able to induce         M2-1 protein-specific CD8⁺ T cells.

FIG. 12: shows that RSV-F mRNA vaccines either alone (RSV-F=R2510; RSV-Fdel554-574 mutant=R2821) or in combination with mRNAs encoding other RSV proteins (RSV-N=R2831; RSV-M2-1=R2833) induce humoral immune responses in cotton rats.

-   -   The experiment was performed as described in Example 6 and RSV-F         specific total IgG antibody titers were determined by ELISA on         day 49. Serum was analyzed in different dilution, as given below         the graph.

FIG. 13: shows that RSV-F mRNA vaccines either alone (RSV-F, R2510; RSV-Fdel554-574 mutant, R2821) or in combination with mRNAs encoding other RSV proteins (RSV-N=R2831; RSV-M2-1=R2833) induce the formation of functional antibodies in cotton rats as shown by virus neutralizing antibody titers.

-   -   The experiment was performed as described in Example 6 and virus         neutralizing titers on day 49 were determined by plaque         reduction assay.

FIGS. 14A-B: show that RSV-F mRNA vaccines either alone (RSV-F=R2510; RSV-Fdel554-574 mutant=R2821) or in combination with mRNAs encoding other RSV proteins (RSV-N=R2831; RSV-M2-1=R2833) reduce lung and nasal titers in cotton rats challenged with RSV virus.

-   -   The experiment was performed as described in Example 6.     -   (A) Lung titers on day 5 after RSV challenge infection. All         animal groups vaccinated with mRNA vaccines showed virus titers         below the level of detection of the performed virus titration         demonstrating protection of vaccinated cotton rats in terms of         viral lung titers. In comparison to the mRNA vaccines the         vaccine based on formalin-inactivated virus were not able to         prevent virus titers in the lung.     -   (B) Nasal titers on day 5 after RSV challenge infection. The         viral titer in the nasal tissue was also strongly reduced in         groups vaccinated with mRNA. In comparison to the mRNA vaccines         the vaccine based on formalin-inactivated virus were not able to         reduce the nasal virus titers.

FIG. 15: shows the results of the lung histopathology analysis from the RSV cotton rat challenge study described in Example 6.

FIGS. 16A-D: show the results of the quantitative reverse transcription polymerase chain reaction (RT-PCR) of viral genome copy numbers (by measuring copy numbers of the RSV NS-1 gene) or expressed cytokines from lung tissue of the RSV infected animals (or controls) of the RSV cotton rat challenge study described in Example 6.

FIGS. 17A-B: show that RSV-F mRNA vaccines (RSV-F=R2510; RSV F* (RSV-Fdel554-574 mutant)=R2821) reduce lung titers in cotton rats challenged with RSV virus.

-   -   The experiment was performed as described in Example 7.     -   (A) Lung titers on day 5 after RSV challenge infection. All         animal groups vaccinated intradermally with mRNA vaccines showed         reduced virus titers compared to the buffer control group         demonstrating protection of vaccinated cotton rats in terms of         viral lung titers. Already one single dose of RSV-F mRNA         vaccines efficiently reduced viral titers in the lung.     -   (B) Lung titers on day 5 after RSV challenge infection. The         viral titer in the lung was also strongly reduced in groups         intramuscularly vaccinated with mRNA.

EXAMPLES

The examples shown in the following are merely illustrative and shall describe the present invention in a further way. These examples shall not be construed to limit the present invention thereto.

Example 1 Preparation of the mRNA Vaccine

1. Preparation of DNA and mRNA Constructs

For the present examples DNA sequences, encoding the RSV-F protein (R1691 and R2510), the RSV-F del554-574 (R2821) mutant protein, the RSV N-protein (R2831) and the RSV M2-1 protein (R2833) of the RSV long strain were prepared and used for subsequent in vitro transcription reactions. The RSV-Fdel554-574 mutant protein has been described previously (Oomens et al. 2006. J. Virol. 80(21):10465-77).

According to a first preparation, the DNA sequences coding for the above mentioned mRNAs were prepared. The construct R1691 was prepared by modifying the wild type coding sequence by introducing a GC-optimized sequence for stabilization, followed by a stabilizing sequence derived from the alpha-globin-3′-UTR (muag (mutated alpha-globin-3′-UTR) according to SEQ ID No. 29), a stretch of 64 adenosines (poly(A)-sequence), a stretch of 30 cytosines (poly(C)-sequence), and a histone stem loop according to SEQ ID No. 30. In SEQ ID NO: 31 (see FIG. 1) the sequence of the corresponding mRNA is shown. The constructs R2510, R2821, R2831 and R2833 were prepared by introducing a 5′-TOP-UTR derived from the ribosomal protein 32L according to SEQ ID No. 23, modifying the wild type coding sequence by introducing a GC-optimized sequence for stabilization, followed by a stabilizing sequence derived from the albumin-3′-UTR (albumin7 according to SEQ ID No. 25), a stretch of 64 adenosines (poly(A)-sequence), a stretch of 30 cytosines (poly(C)-sequence), and a histone stem loop according to SEQ ID No. 30. In SEQ ID NOs: 32-35 (see FIG. 2-5) the sequences of the corresponding mRNAs are shown.

TABLE 1 mRNA constructs RNA Antigen FIG. SEQ ID NO. R1691 RSV F 1 SEQ ID NO. 31 R2510 RSV F 2 SEQ ID NO. 32 R2821 RSV Fdel554-574 3 SEQ ID NO. 33 R2831 RSV N 4 SEQ ID NO. 34 R2833 RSV M₂₋₁ 5 SEQ ID NO. 35

2. In Vitro Transcription

The respective DNA plasmids prepared according to paragraph 1 were transcribed in vitro using T7 polymerase in the presence of a CAP analog (m⁷GpppG). Subsequently the mRNA was purified using PureMessenger® (CureVac, Tubingen, Germany; WO2008/077592A1).

3. Reagents

Complexation Reagent: protamine

4. Preparation of the Vaccine

The mRNA was complexed with protamine by addition of protamine to the mRNA in the ratio (1:2) (w/w) (adjuvant component). After incubation for 10 minutes, the same amount of free mRNA used as antigen-providing RNA was added.

For example: RSV-F long vaccine (R1691): comprising an adjuvant component consisting of mRNA coding for RSV F protein long (R1691) according to SEQ ID NO. 31 complexed with protamine in a ratio of 2:1 (w/w) and the antigen-providing free mRNA coding for RSV F protein long (R1691) according to SEQ ID NO. 31 (ratio 1:1; complexed RNA:free RNA).

Example 2 Induction of a Humoral Immune Response by the RSV-F Long mRNA Vaccine in Mice

Immunization

On day zero, BALB/c mice were intradermally (i.d.) injected with the RSV-F long mRNA vaccine (R1691 according to Example 1; 25 μg/mouse/vaccination day) or Ringer-lactate (RiLa) as buffer control as shown in Table 2. A control group was intramuscularly (i.m.) injected with 10 μg of the inactivated RSV long vaccine. The inactivated “Respiratory Syncytial Virus Antigen” (inactivated RSV long) was purchased from the INSTITUT VIRION/SERION GmbH-SERION IMMUNDIAGNOSTICA GmbH. The inactivated virus was diluted in sterile PBS, so that a final concentration of 0.2 μg/μL was achieved. All animals received boost injections on day 14 and day 28. Blood samples were collected on day 42 for the determination of anti-RSV F antibody titers.

TABLE 2 Animal groups Strain No. Route Vaccine Vaccination Group sex mice volume dose schedule 1 BALB/c 5 i.d. R1691 d0: prime, Female 2 × 50 μl 2 μg d14: boost, d28: boost, d42: blood collection 2 BALB/c 5 i.m. Inactivated RSV d0: prime, Female 2 × 25 μl long d14: boost, 10 μg d28: boost, d42: blood collection 3 BALB/c 5 i.d. 80% Ringer d0: prime, Female 2 × 50 μl Lactate (RiLa) d14: boost, buffer d28: boost, d42: blood collection

Determination of Anti-RSV F Protein Antibodies by ELISA

ELISA plates are coated with recombinant human RSV fusion glycoprotein (rec.hu F-protein, final conc.: 5 μg/mL) (Sino Biological Inc.). Coated plates are incubated using given serum dilutions and binding of specific antibodies to the F protein is detected using biotinylated isotype specific anti-mouse antibodies in combination with streptavidin-HRP (horse radish peroxidase) with ABTS substrate.

Results

As can be seen in FIG. 6, the RSV-F long mRNA vaccine induces antibody titers (total IgG, IgG1 and IgG2a) against the RSV F protein comparable to those against inactivated RSV.

Example 3 Induction of a Long-Lived Humoral Immune Response by the RSV-F Long mRNA Vaccine in Mice

Immunization

BALB/c mice were intradermally (i.d.) injected with 20 μg of the RSV-F long mRNA vaccine (R1691) or Ringer Lactate (RiLa) buffer according to the vaccination schedule shown in Table 3. Blood was collected 2 weeks, 4 months and 11 months after the last immunization.

TABLE 3 Animal groups Strain Number Route Vaccine Vaccination schedule Group sex of mice volume dose (day) 1 BALB/c 5 i.d. R1691 d0, d14, d28 Female 100 μl 20 μg 4 BALB/c 5 i.d. 80% RiLa d0, d14, d28 Female 100 μl buffer

Results

As can be seen in FIG. 7, the RSV-F long mRNA vaccine induced a long-lived immune response as demonstrated by stable antibody titers for at least 11 months after the last boost vaccination.

Example 4 Induction of a Cellular Immune Response by the RSV-F Long mRNA Vaccine in Mice

Immunization

On day zero, BALB/c mice were intradermally (i.d.) injected with the RSV-F long mRNA vaccine R1691 (20 μg/mouse/vaccination day) or Ringer-lactate (RiLa) as buffer control as shown in Table 4. A control group was intramuscularly (i.m.) injected with 10 μg of the inactivated RSV long vaccine. The inactivated “Respiratory Syncytial Virus Antigen” (inactivated RSV long) was purchased from the INSTITUT VIRION/SERION GmbH-SERION IMMUNDIAGNOSTICA GmbH. The inactivated virus was diluted in sterile PBS, so that a final concentration of 0.2 μg/μL was achieved.

All animals received boost injections on days 14 and 28. Spleens were collected on day 34 for the analysis of antigen-specific T cells.

TABLE 4 Animal groups Strain Number Route Vaccine Vaccination Group sex of mice volume dose schedule 1 BALB/c 5 i.d. R1691 d0: prime, Female 2 × 50 μl 20 μg d14: boost, d28: boost, d34: spleen collection 2 BALB/c 5 i.m. Inactivated d0: prime, Female 2 × 25 μl RSV long d14: boost, 10 μg d28: boost, d34: spleen collection 3 BALB/c 5 i.d. Ringer Lactate d0: prime, Female 2 × 50 μl (RiLa) buffer d14: boost, d28: boost, d34: spleen collection

Intracellular Cytokine Staining

Splenocytes from vaccinated and control mice were isolated according to a standard protocol. Briefly, isolated spleens were grinded through a cell strainer and washed in PBS/1% FBS followed by red blood cell lysis. After an extensive washing step with PBS/1% FBS splenocytes were seeded into 96-well plates (2×10⁶ cells/well). The next day cells were stimulated with a RSV-F peptide (KYKNAVTEL; 5 μg/ml; H-2kd-restructed T-cell epitope) or an irrelevant control peptide derived from the influenza HA protein (IYSTVASSL; 5 μg/ml; purchased from EMC Microcollections) and 2.5 μg/ml of an anti-CD28 antibody (BD Biosciences) for 6 hours at 37° C. in the presence of the mixture of GolgiPlug™/GolgiStop™ (Protein transport inhibitors containing Brefeldin A and Monensin, respectively; BD Biosciences). After stimulation cells were washed and stained for intracellular cytokines using the Cytofix/Cytoperm reagent (BD Biosciences) according to the manufacturer's instructions. The following antibodies were used for staining: CD8-PECy7 (1:200), CD3-FITC (1:200), IL2-PerCP-Cy5.5 (1:100), TNFα-PE (1:100), IFNγ-APC (1:100) (eBioscience), CD4-BD Horizon V450 (1:200) (BD Biosciences) and incubated with Fcγ-block diluted 1:100. Aqua Dye was used to distinguish live/dead cells (Invitrogen). Cells were collected using a Canto II flow cytometer (Beckton Dickinson). Flow cytometry data were analysed using FlowJo software (Tree Star, Inc.). Statistical analysis was performed using GraphPad Prism software, Version 5.01. Statistical differences between groups were assessed by the Mann Whitney test.

Results

As can be seen from FIG. 8, the RSV-F long mRNA vaccine (R1691) induced IFNγ positive, TNFα positive and IFNγ/TNFα double-positive multifunctional CD8⁺ T cells directed against RSV F protein. Surprisingly the vaccine based on inactivated RSV virus was not able to induce antigen-specific CD8⁺ T cells.

Example 5 Induction of Cellular Immune Responses by the RSV-N and RSV-M₂₋₁ mRNA Vaccines in Mice

Immunization

On day zero, BALB/c mice were intradermally (i.d.) injected with different doses of the RSV-N mRNA vaccine R2831, the RSV-M2-1 mRNA vaccine R2833 or Ringer-lactate (RiLa) as buffer control as shown in Table 5. A control group was intramuscularly (i.m.) injected with 10 μg of the inactivated RSV long vaccine. The inactivated “Respiratory Syncytial Virus Antigen” (inactivated RSV long) was purchased from the INSTITUT VIRION/SERION GmbH-SERION IMMUNDIAGNOSTICA GmbH. The inactivated virus was diluted in sterile PBS, so that a final concentration of 0.2 μg/μL was achieved. All animals received boost injections on days 7 and 21. Spleens were collected on day 27 for the analysis of antigen-specific T cells.

TABLE 5 Animal groups Strain No. Route Vaccine Group sex mice volume dose Vaccination schedule 1 BALB/c 5 i.d. R2831 RSV-N d0: prime, d7: boost, d21: boost, Female 1 × 50 μl 40 μg d27: spleen collection 2 BALB/c 5 i.d. R2831 RSV-N d0: prime, d7: boost, d21: boost, Female 1 × 25 μl 20 μg d27: spleen collection 3 BALB/c 5 i.d. R2831 RSV-N d0: prime, d7: boost, d21: boost, Female 1 × 12.5 μl 10 μg d27: spleen collection 4 BALB/c 5 i.d. R2833 RSV-M₂₋₁ d0: prime, d7: boost, d21: boost, Female 1 × 50 μl 40 μg d27: spleen collection 5 BALB/c 5 i.d. R2833 RSV-M₂₋₁ d0: prime, d7: boost, d21: boost, Female 1 × 25 μl 20 μg d27: spleen collection 6 BALB/c 5 i.d. R2833 RSV-M₂₋₁ d0: prime, d7: boost, d21: boost, Female 1 × 12.5 μl 10 μg d27: spleen collection 7 BALB/c 5 i.m. Inactiv. RSV d0: prime, d7: boost, d21: boost, Female 2 × 25 μl long d27: spleen collection 10 μg 8 BALB/c 5 i.d. 100% RiLa d0: prime, d7: boost, d21: boost, Female 1 × 50 μl buffer d27: spleen collection

Intracellular cytokine staining was performed as described in Example 4 except that cells were treated with the following stimulators at:

M2-1 peptide (5 μg/ml) group 4 to 8; (SYIGSINNI from Proimmune); ProMix N (1 μg/ml) 1-3, group 7 and 8; (PX39 from Proimmune); control: medium+DMSO+anti-CD28, group 1-8 as descripted above.

Results

As can be seen from FIG. 9, the RSV-N mRNA vaccine (R2831) induced IFNγ positive, TNFα positive and IFNγ/TNFα double-positive multifunctional CD8⁺ T cells directed against RSV N protein in mice.

Surprisingly the vaccine based on inactivated RSV virus was not able to induce antigen-specific CD8⁺ T cells.

As can be seen from FIG. 10, the RSV-N mRNA vaccine (R2831) induced IFNγ positive, TNFα positive and IFNγ/TNFα double-positive multifunctional CD4⁺ T cells directed against RSV N protein in mice.

Surprisingly the vaccine based on inactivated RSV virus was not able to induce antigen-specific CD4⁺ T cells.

As can be seen from FIG. 11, the RSV-M2-1 mRNA vaccine (R2833) induced IFNγ positive, TNFα positive and IFNγ/TNFα double-positive multifunctional CD8⁺ T cells directed against RSV M₂₋₁ protein in mice.

Surprisingly the vaccine based on inactivated RSV virus was not able to induce antigen-specific CD8⁺ T cells.

Example 6 RSV Cotton Rat Challenge Study I

For the development of RSV vaccines the cotton rat is an accepted animal model, especially for the challenge infection. Cotton rats respond to formalin-inactivated RSV virus vaccine preparations with enhanced lung pathology. This allows the evaluation of the safety of a vaccination in terms of enhanced disease phenomenon.

To broaden and optimize the RSV-specific immune response, mRNA vaccines encoding different RSV proteins (RSV F, mutant RSV-Fdel554-574, N and M2-1) were prepared according to Example 1. In order to assess the effect of single or combined vaccines, these vaccines were administered either alone or in combination (cocktail vaccine) as shown in Table 5. Vaccine volumes of 2×50 μl were injected intradermally (i.d.) into the back skin of cotton rats. Additional groups were immunized intramuscularly (i.m.) with β-propiolactone inactivated RSV (INSTITUT VIRION/SERION GmbH-SERION IMMUNDIAGNOSTICA GmbH), formalin-inactivated RSV (Sigmovir) or live RSV/A2 (Sigmovir) (10⁵ plaque forming units, pfu) to compare their immunogenicity to mRNA vaccines. Another group received i.m. injections of the monoclonal anti-RSV antibody SYNAGIS® (Palivizumab) as passive immunization. SYNAGIS® was administered with a dose of 15 mg/kg on the day prior to RSV challenge infection. Therefore the animals were weighed and the appropriate amount of SYNAGIS® was calculated according to the animals' weight. The maximal volume for i.m. injection was 200 μl per 100 g rat. After immunization the cotton rats were challenged by intranasal (i.n.) infection with RSV/A2 virus (10⁵ PFU in 100 μl; Sigmovir).

TABLE 5 Animal groups Vaccine # of N per Vaccination Bleed Groups dose Volume Antigen Route administrations group (day) (day) A β-   100 μl — IM 3 5 0, 14, 28 14, 28, 49 propiolactone inactivated RSV 20 μg B R2510 2 × 50 μl RSV F ID 3 5 0, 14, 28 14, 28, 49 80 μg C R2821 2 × 50 μl RSV F ID 3 5 0, 14, 28 14, 28, 49 80 μg mutant D R2510 + 2 × 50 μl RSV F + ID 3 5 0, 14, 28 14, 28, 49 R2831 RSV N “cocktail I” each 40 μg E R2510 + 2 × 50 μl RSV F + ID 3 5 0, 14, 28 14, 28, 49 R2833 RSV “cocktail II” M₂₋₁ each 40 μg F R2510 + 2 × 50 μl RSV F + ID 3 5 0, 14, 28 14, 28, 49 R2831 + R2833 RSV “cocktail III” M₂₋₁ + each 26.666 μg RSV N G RiLa 2 × 50 μl — ID 3 5 0, 14, 28 14, 28, 49 H FI-RSV   100 μl — IM 2 5 0, 28 28, 49 Lot#100 (diluted 1:100 in PBS) I Live RSV/A2   100 μl — IM 1 5  0 49 10⁵ pfu J SYNAGIS ® — IM 1 5 48 49 (15 mg/kg) K Neg. control — N/A N/A 5 — —

The following assays were performed to analyze the immune responses: RSV F-protein serum IgG ELISA, RSV virus neutralizing antibody titers (VNT), RSV viral titrations and pulmonary histopathology.

RSV F-Protein Serum IgG ELISA

The induction of anti-RSV F protein antibodies were determined by ELISA according to Example 2.

RSV Virus Neutralizing Antibody Titers (VNT)

Sera were analysed by the virus neutralization test (VNT). Briefly, sera samples were diluted 1:10 with EMEM, heat inactivated and serially diluted further 1:4. Diluted sera samples were incubated with RSV (25-50 PFU) for 1 hour at room temperature and inoculated in duplicates onto confluent HEp-2 monolayers in 24 well plates. After one hour incubation at 37° C. in a 5% CO₂ incubator, the wells were overlayed with 0.75% Methylcellulose medium. After 4 days of incubation, the overlay was removed and the cells were fixed with 0.1% crystal violet stain for one hour and then rinsed and air dried. The corresponding reciprocal neutralizing antibody titers were determined at the 60% reduction end-point of the virus control.

RSV Viral Titrations and Pulmonary Histopathology

On day 54 nasal tissue was harvested and homogenized for viral titrations. The lung was harvested en bloc and tri-sected for viral titration (left section), histopathology (right section), and PCR analysis (lingular lobe). In addition, RSV viral genome copy numbers (by measuring copy numbers of the RSV NS-1 gene) and cytokine mRNA levels were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results

As can be seen from FIG. 12, the RSV-F mRNA vaccines either alone (RSV-F=R2510; RSV-Fdel554-574 mutant=R2821) or in combination with mRNAs encoding other RSV proteins (RSV-N=R2831; RSV-M2-1=R2833), induce RSV F specific humoral immune responses in cotton rats as shown by total IgG antibody titers on day 49.

As can be seen from FIG. 13, the RSV-F mRNA vaccines either alone (RSV-F=R2510; RSV-Fdel554-574 mutant=R2821) or in combination with mRNAs encoding other RSV proteins (RSV-N, R2831=RSV-M2-1=R2833), induce the formation of RSV specific functional antibodies in cotton rats as shown by virus neutralizing antibody titers.

As can be seen from FIG. 14, the RSV-F mRNA vaccines either alone (RSV-F=R2510; RSV-Fdel554-574 mutant=R2821) or in combination with mRNAs encoding other RSV proteins (RSV-N=R2831; RSV-M2-1=R2833), reduce lung and nasal viral titers in cotton rats challenged with RSV virus.

As can be seen in FIG. 14A, all animal groups vaccinated with mRNA vaccines showed virus titers below the level of detection of the performed virus titration demonstrating protection of vaccinated cotton rats in terms of viral lung titers. By contrast, the Formalin-inactivated virus vaccine reduced only minimally the lung virus titer compared to the RiLa buffer control group. The effect of the β-propiolactone inactivated RSV vaccine was more pronounced but did not reduce the virus lung titer below the detection level in all animals of this group. As can be seen in FIG. 14B, the viral titer in the nasal tissue was also strongly reduced in groups vaccinated with mRNA. Nasal viral titers of the Formalin-inactivated virus were comparable to the viral titer in the RiLa vaccinated group. The β-propiolactone inactivated virus vaccine was more effective (at least for two of five animals). In contrast thereto, all mRNA vaccinated groups had reduced nasal virus titer compared to RiLa vaccinated group.

As can be seen from FIG. 15, the lung histopathology analysis from the RSV cotton rat challenge study reveals different pathology scores for the various animal groups. From the histopathology it can be concluded that none of the mRNA vaccinated groups displayed enhanced lung pathology as it is the case for the group that was vaccinated using the Formalin-inactivated RSV vaccine. The average pathology scores for peribronchiolitis (PB), perivasculitis (PV), insterstitial pneumonia (IP) and alveolitis (A) are much lower for all groups vaccinated with mRNA compared to group H (Formalin-inactivated RSV). In addition the groups being vaccinated with R2510 (group B; RSV F) or R2821 (group C; RSV F mutant) seem to exhibit reduced lung pathology compared to the RiLa buffer vaccinated and subsequently RSV infected group (G).

As can be seen in FIG. 16, the quantitative RT-PCR reveals different expression patterns for the various animal groups. The quantification of RSV genome copies by measuring the RSV NS-1 gene is displayed in A. Genome copy numbers are reduced by vaccination using mRNA vaccines compared to the RiLa buffer control (group G). This is not the case for the group that was vaccinated using formalin-inactivated-RSV (group H). As it is shown in B, the vaccination using the formalin-inactivated-RSV vaccine (group H) induces enhanced expression of the TH2 cytokine IL-4 compared to the control group that was vaccinated with RiLa buffer (group G). By contrast, the vaccination with mRNA R2821 encoding the RSV-F mutant significantly reduced IL-4 mRNA expression compared to the RiLa control group in the lung after RSV challenge infection. C. Expression of INF-γ□mRNA. D. Expression of IL-5 mRNA. The expression of IL-5 is significant reduced in groups vaccinated using R2510 or R2821 compared to RiLa buffer vaccinated animals. The expression of the viral NS-1 RNA or cytokine mRNAs, which were isolated from lung tissue, is measured on day 5 post-challenge. The statistical analysis was performed with the student T-test (* p<0.05 when compared to group G (RiLa control)).

Example 7 RSV Cotton Rat Challenge Study II

mRNA vaccines encoding RSV F protein (F) or mutant RSV-F protein (F*) (RSV F del554-574) were prepared according to Example 1. In order to assess the effect of single or several vaccinations (prime and boost vaccinations), these vaccines were administered once, twice or 3 times (as shown in Table 6). Vaccine volumes of 2×50 μl were injected intradermally (i.d.) into the back skin of cotton rats. Additional groups were immunized intramuscularly (i.m.) with vaccine volumes of 1×100 μl into the right hind leg. As a control, one group was injected intradermally with Ringer-Lactate buffer (buffer). After immunization, the cotton rats were challenged by intranasal (i.n.) infection with RSV/A2 virus (10⁵ PFU in 100 μl; Sigmovir). As a control, one group was not treated and remained unchallenged with virus (untreated).

TABLE 5 Animal groups Vaccine # of N per Vaccination Challenge Groups dose Volume Antigen Route administrations group (day) (day) F* i.d. 3x R2821 2 × 50 μl RSV F ID 3 5 0, 14, 28 49 80 μg mutant F* i.d. 2x R2821 2 × 50 μl RSV F ID 2 5 0, 14 49 80 μg mutant F* i.d. 1x R2821 2 × 50 μl RSV F ID 1 5 0 49 80 μg mutant F i.d. 3x R2510 2 × 50 μl RSV F ID 3 5 0, 14, 28 49 80 μg F i.d. 2x R2510 2 × 50 μl RSV F ID 2 5 0, 14 49 80 μg F i.d. 1x R2510 2 × 50 μl RSV F ID 1 5 0 49 80 μg F* i.m. R2821 1 × 100 μl  RSV F IM 2 5 0, 14 49 80 μg mutant F i.m. R2510 1 × 100 μl  RSV F IM 2 5 0, 14 49 80 μg Buffer — 2 × 50 μl ID 3 5 0, 14, 28 49 untreated — — N/A N/A 5 — —

RSV Viral Titrations

The determination of RSV viral titers was conducted as described in Example 6.

Results

As shown in FIG. 17A, already one single intradermal vaccination with mRNA vaccines coding for RSV F protein (F) or mutant RSV-F protein (F*) (RSV F del554-574) was highly efficient in reducing the viral titer in the lung compared to the buffer control group. A second and third vaccination (“boost vaccinations) reduced the viral titers below detection level.

As shown in FIG. 17B, already two intramuscular vaccinations with mRNA vaccines coding for RSV F protein (F) or mutant RSV-F protein (F*) (RSV F del554-574) strongly reduced the viral titer in the lung compared to the buffer control group. 

The invention claimed is:
 1. A method of treatment or prophylaxis of Respiratory syncytial virus (RSV) infections comprising the steps: a) Providing the mRNA sequence encoding at least one antigenic polypeptide from the fusion protein F, the nucleoprotein N, the M2-1 protein or the M2-2 protein of RSV, wherein the G/C content of the sequence encoding the antigenic polypeptide is increased compared with the G/C content of the coding region of the wild type mRNA encoding an antigenic polypeptide; and b) applying or administering the mRNA sequence to a subject; wherein the mRNA sequence encoding the antigenic polypeptide comprises a sequence at least 90% identical to one of Seq. Id. Nos. 31, 32, 33, 34, or
 35. 2. The method according to claim 1, wherein the mRNA further comprising a 5′-cap structure, a poly(A) sequence, and/or a poly(C) sequence.
 3. The method according to claim 2, wherein the 5′cap structure is m7GpppN.
 4. The method according to claim 2, wherein the poly(A) sequence comprises a sequence of 25 to 400 adenosine nucleotides.
 5. The method according to claim 1, wherein the mRNA further comprises at least one histone stem-loop.
 6. The method according to claim 1, wherein the mRNA sequence further comprises a stabilizing sequence from the alpha globin 3′ UTR, positioned 3′ relative to the coding region of the mRNA sequence.
 7. The method according to claim 1, wherein the mRNA sequence comprises from a 5′ to 3′: a 5′-cap structure, a 5′ UTR sequence, the sequence encoding the at least one antigenic polypeptide, a 3′ UTR, a poly(A) sequence, a poly(C) sequence and a histone stem-loop sequence.
 8. The method according to claim 1, wherein the at least one antigenic polypeptide is from the RSV fusion protein F.
 9. The method according to claim 1, wherein the mRNA sequence is complexed with a cationic or polycationic compound.
 10. The method according to claim 9, wherein the cationic or polycationic compound is protamine, poly-L-lysine (PLL), or poly-arginine.
 11. The method according to claim 9, wherein the cationic or polycationic compound is protamine.
 12. The method according to claim 9, wherein the weight ratio of the mRNA sequence to the cationic or polycationic compound is in the range from 6:1 to 0.25:1.
 13. The method of claim 1, wherein the mRNA sequence is administered by injection.
 14. The method of claim 13, wherein the mRNA sequence is administered by intradermal or intramuscular injection.
 15. The method of claim 1, wherein the mRNA sequence is formulated in a Ringer's lactate solution.
 16. The method of claim 1, further comprising administering mRNA sequences encoding at least 2 different antigenic polypeptides from RSV.
 17. The method of claim 16, wherein the mRNA sequences encoding the at least 2 different antigenic polypeptides are administered separately.
 18. The method of claim 16, wherein the mRNA sequences encoding the at least 2 different antigenic polypeptides are administered in the same formulation.
 19. The method according to claim 1, wherein the mRNA sequence encoding the antigenic polypeptide comprises a sequence at least 95% identical to SEQ ID NO: 31, 32, 33, 34 or
 35. 20. The method according to claim 19, wherein the mRNA sequence encoding the antigenic polypeptide comprises a sequence according to SEQ ID NO: 31, 32, 33, 34 or
 35. 21. The method of claim 1, further defined as method for inducing RSV-specific T-cell response in the subject. 